2009 Vol. 33 No. 4
Open Access
2009, 33(4): 571-575.
Abstract：
The spiny eel (Mastacem belus aculeatus) is a species of the genusMastacembelus (Osteichthyes, Perciformes), whichmainly live in the freshwater of the south ofChina1 The fish isparticularly attractive for cytogenetical study ow ing to possessing well differentiated X and Y sex chromosomes.In the present study, the X chromosomesofM. aculeatus werem icrodissected from themetaphasesof chromosomes of the female. Then, the fragments of X chromosomeswere put into am icro tube and amplified using Degenerated Oligonucleotide-Primed PCR (DOP-PCR). Thereafter, the product of PCR was connected to T vector and the plasm idswere electric transformed into E1 coli1 As a resul,t the library of X chromosome ofM. aculeatus was constructed. The sum of the lengths of the inserted fragments is some 1.08 ?108bp, w ith an average length of 500bp. It is believed that the library coveredmore than 98% sequences of the whole X chromosome theoretically.To check the credibility of the library, fluorescence in situ hybridization (FISH) was applied. The fragmentsof the library were labeledw ith biotin by PCR. Then the probeswere hybridized to the chromosomem etaphases ofboth sex ofM 1 aculeatus in the absence or the presence of competitorDNA1 Strong signalswere detected on the entire sex chromosomes aswell as signals dispersed on all autosomesw ith the condition of FISH in the absence of competitor DNA.W hereas competitorDNA was added, the signals disappeared except those showed on heterochrom atic regions of X and Y chromosomes.H ence, we assorted the repetitive sequences in theX chromosom e ofM. aculeatus into three types. It was interpreted that the signalsof FISH in the presence of competitor DNA showed the distribution of typerepetitive sequences on the sex chromosomes ofM. aculeatus.
The spiny eel (Mastacem belus aculeatus) is a species of the genusMastacembelus (Osteichthyes, Perciformes), whichmainly live in the freshwater of the south ofChina1 The fish isparticularly attractive for cytogenetical study ow ing to possessing well differentiated X and Y sex chromosomes.In the present study, the X chromosomesofM. aculeatus werem icrodissected from themetaphasesof chromosomes of the female. Then, the fragments of X chromosomeswere put into am icro tube and amplified using Degenerated Oligonucleotide-Primed PCR (DOP-PCR). Thereafter, the product of PCR was connected to T vector and the plasm idswere electric transformed into E1 coli1 As a resul,t the library of X chromosome ofM. aculeatus was constructed. The sum of the lengths of the inserted fragments is some 1.08 ?108bp, w ith an average length of 500bp. It is believed that the library coveredmore than 98% sequences of the whole X chromosome theoretically.To check the credibility of the library, fluorescence in situ hybridization (FISH) was applied. The fragmentsof the library were labeledw ith biotin by PCR. Then the probeswere hybridized to the chromosomem etaphases ofboth sex ofM 1 aculeatus in the absence or the presence of competitorDNA1 Strong signalswere detected on the entire sex chromosomes aswell as signals dispersed on all autosomesw ith the condition of FISH in the absence of competitor DNA.W hereas competitorDNA was added, the signals disappeared except those showed on heterochrom atic regions of X and Y chromosomes.H ence, we assorted the repetitive sequences in theX chromosom e ofM. aculeatus into three types. It was interpreted that the signalsof FISH in the presence of competitor DNA showed the distribution of typerepetitive sequences on the sex chromosomes ofM. aculeatus.
Open Access
2009, 33(4): 577-580.
Abstract：
In the study of microbiology, the activity and the number of microbial cells are often determined to reflect the growth ofmicrobial cells. The conventionalmethods usually include plate culturemethod, the cell numberof automatic analyzer, turbidity, dry cellweight and biological fluorescence method, and so on1 Among these conventionalmethods, the plate culture method is cumbersome, time-consuming and poor reproducibility, and most importantly, it can not truly reflect the growth of bacteria, furthermore, it is not suitable for bigger quantities experiment1 For the other conventional methods, they even could not distinguish between live and dead cells, and the number and activity of cells are vulnerable to the medium and metabolites1 In recent years, MTT colorimetric method is used to evaluate the microbial cell activity, which ismore simple, rapid, sensitive and stable compared with the conventionalmethods1 The principle is that the livingcells can reduce MTT to a blue-violetmatter bymitochondrial dehydrogenase in cells, the matter has the optical absorption value from 560 nm to 610 nm, and most reports indicate that blue2violet matter have the best optical absorption value at 570 nm. MTT colorimetricmethod was always used to detect the activity of immune cells and other animal cells, but itwas rarely reported in the detection of the activity of themicrobial cells1 In this paper, MTT colorimetricmethod for quantification of microbial cell viability or cell growth in microplateswas discussed1 Escherichia coliwas employed to determine theconditions of assay, which included the feasibility, reaction periods, microbial cell number, the concentration ofMTT andso on1 Itwas found thatMTT had a high correlation between the values of OD570 and the microbial cell number, which wasfrom 4.9 ×107 cells/mL to 4.19 ×108 cells/mL. The correlation was the bestwhen bacteria was treated with MTT 0.5 mg/mL of 20μL for 20 min, and the correlation and regression equation was y = 0.1769x + 0.03, R2= 0.9983; when bacteria was treated with MTT 5 mg/mL of 20μL for 30 min, the correlation and regression equation was y = 0.4032x +0.0143 R2= 0.998.MTT colorimetricmethod is economic, simple, fast, stable, high sensitive, and the results can showthe numberof live micro-organisms or cells activity clearly. Previous studies also showed that MTT colorimetricmethod wassuperior to other color, such as the TTC, INT, XTT, blade, etc1 among evaluation methods of cell viability.
In the study of microbiology, the activity and the number of microbial cells are often determined to reflect the growth ofmicrobial cells. The conventionalmethods usually include plate culturemethod, the cell numberof automatic analyzer, turbidity, dry cellweight and biological fluorescence method, and so on1 Among these conventionalmethods, the plate culture method is cumbersome, time-consuming and poor reproducibility, and most importantly, it can not truly reflect the growth of bacteria, furthermore, it is not suitable for bigger quantities experiment1 For the other conventional methods, they even could not distinguish between live and dead cells, and the number and activity of cells are vulnerable to the medium and metabolites1 In recent years, MTT colorimetric method is used to evaluate the microbial cell activity, which ismore simple, rapid, sensitive and stable compared with the conventionalmethods1 The principle is that the livingcells can reduce MTT to a blue-violetmatter bymitochondrial dehydrogenase in cells, the matter has the optical absorption value from 560 nm to 610 nm, and most reports indicate that blue2violet matter have the best optical absorption value at 570 nm. MTT colorimetricmethod was always used to detect the activity of immune cells and other animal cells, but itwas rarely reported in the detection of the activity of themicrobial cells1 In this paper, MTT colorimetricmethod for quantification of microbial cell viability or cell growth in microplateswas discussed1 Escherichia coliwas employed to determine theconditions of assay, which included the feasibility, reaction periods, microbial cell number, the concentration ofMTT andso on1 Itwas found thatMTT had a high correlation between the values of OD570 and the microbial cell number, which wasfrom 4.9 ×107 cells/mL to 4.19 ×108 cells/mL. The correlation was the bestwhen bacteria was treated with MTT 0.5 mg/mL of 20μL for 20 min, and the correlation and regression equation was y = 0.1769x + 0.03, R2= 0.9983; when bacteria was treated with MTT 5 mg/mL of 20μL for 30 min, the correlation and regression equation was y = 0.4032x +0.0143 R2= 0.998.MTT colorimetricmethod is economic, simple, fast, stable, high sensitive, and the results can showthe numberof live micro-organisms or cells activity clearly. Previous studies also showed that MTT colorimetricmethod wassuperior to other color, such as the TTC, INT, XTT, blade, etc1 among evaluation methods of cell viability.
Open Access
2009, 33(4): 581-588.
Abstract：
Expressed sequence tag (EST) analysis is an efficient tool for gene discovery and for profiling geneexpression. In order to isolate specific functional genes involved in reproduction and endocrine regulation and to reveal their evolutionary mechanisms in Chinese sturgeon (Acipenser sinensis Gray), a chondrostean fish with a history of 140 million years, we constructed its pituitary cDNA library from a 4 year-old male1 A total of 944 random cloneswere sequenced and compared with sequences in GenBank database1 Among all the 944 EST clones, 802 (84196%) clones were identified as 461 known genes, and additional 142 (15104%) as unknown genes. Functional categorization indicated that the most abundantly expressed functional gene was the proopiomelanocortin (POMC), which accounted for almost10117% of the overall expression, indicating its important function in the pituitary. Interestingly, the expression patterns of 7 unknown geneswere analyzed in various tissues, such as heart, liver, spleen, kidney, muscle, testes, ovary and pituitary. Three different categories of expression patternswere observed from them1 Several unknown ESTs, such as EG009334, EG009337, EG009338 and EG009340, were detected to be pituitary-specific, orpituitary and ovary-specific genes. Further studies on their functions will be very useful for better understanding the mechanisms of sturgeon reproduction biology and endocrinology.
Expressed sequence tag (EST) analysis is an efficient tool for gene discovery and for profiling geneexpression. In order to isolate specific functional genes involved in reproduction and endocrine regulation and to reveal their evolutionary mechanisms in Chinese sturgeon (Acipenser sinensis Gray), a chondrostean fish with a history of 140 million years, we constructed its pituitary cDNA library from a 4 year-old male1 A total of 944 random cloneswere sequenced and compared with sequences in GenBank database1 Among all the 944 EST clones, 802 (84196%) clones were identified as 461 known genes, and additional 142 (15104%) as unknown genes. Functional categorization indicated that the most abundantly expressed functional gene was the proopiomelanocortin (POMC), which accounted for almost10117% of the overall expression, indicating its important function in the pituitary. Interestingly, the expression patterns of 7 unknown geneswere analyzed in various tissues, such as heart, liver, spleen, kidney, muscle, testes, ovary and pituitary. Three different categories of expression patternswere observed from them1 Several unknown ESTs, such as EG009334, EG009337, EG009338 and EG009340, were detected to be pituitary-specific, orpituitary and ovary-specific genes. Further studies on their functions will be very useful for better understanding the mechanisms of sturgeon reproduction biology and endocrinology.
Open Access
Abstract：
The effects of Hydrilla verticillata on water and sediment in eutrophic lake were investigated by a microcosm experiment. The experimentwas conducted with lake water, sediment and H. verticillata collected from Yuehu Lake in Wuhan, China, in 1m ?m ?m outdoor aquaria1 The apical shoots of this specieswere planted at 4 densities (0, 50, 100 and 150 shoots/m2) 1 Dissolved oxygen (DO), pH, total nitrogen (TN), ammonia (NH+4) and total phosphorus (TP) in water column were measured at the 1st, 8th, 21st, 38th and 55th day after initiation of the experiment, respectively, Eh, pH, TN and TP of sedimentwere measured aswell. At the end of the duration, the plantswere harvested and the drybiomasses were measured. The experimental results showed that the dry biomasseswere 52.9, 31.9 and 24.8 times higher at harvest than that at the initiation of the experiment respectively. DO in water column of the treatmentswith plantswas 2.6 times higher than that of the control, pH values also significantly increased up to 9.85 in the density of 150/m2 at the 38th day1 However, the 3 planting densities did not show significant difference in these two parameters1 The concentrations of TN and NH+4 in water column with plants deceased by 90.2% and 70.0% compared with the control respectively, whereas, the differences among the treatments were not significant. TP in water column decreased with planting densities by 38.9% -57.1%, and the differences among treatments were distinct. As a function of radial oxygen releases from root, the Eh values of sediment increased by 58.6-109.4mV with the planting density compared with the control.Whereas, the pH in the 3 treatments decreased sharply during the first 20 days, then increased up to 7.20-7.34, but still lower than that of the control, which could be explained by the releases of root exudates. In addition, the growth of H. verticillata can effectively reduce the TN and TP in the sediment. It is concluded that the existence of H. verticillata can remove nutrition and improve the quality ofwater column and sediment1 However, plant density is a factor need to be considered in revegetation of degraded lakes, because excessive densitymay inhibit the growth of plants1 So harvesting at appropriate time is a necessary measure to enhance the effect of the submerged macrophyte.
The effects of Hydrilla verticillata on water and sediment in eutrophic lake were investigated by a microcosm experiment. The experimentwas conducted with lake water, sediment and H. verticillata collected from Yuehu Lake in Wuhan, China, in 1m ?m ?m outdoor aquaria1 The apical shoots of this specieswere planted at 4 densities (0, 50, 100 and 150 shoots/m2) 1 Dissolved oxygen (DO), pH, total nitrogen (TN), ammonia (NH+4) and total phosphorus (TP) in water column were measured at the 1st, 8th, 21st, 38th and 55th day after initiation of the experiment, respectively, Eh, pH, TN and TP of sedimentwere measured aswell. At the end of the duration, the plantswere harvested and the drybiomasses were measured. The experimental results showed that the dry biomasseswere 52.9, 31.9 and 24.8 times higher at harvest than that at the initiation of the experiment respectively. DO in water column of the treatmentswith plantswas 2.6 times higher than that of the control, pH values also significantly increased up to 9.85 in the density of 150/m2 at the 38th day1 However, the 3 planting densities did not show significant difference in these two parameters1 The concentrations of TN and NH+4 in water column with plants deceased by 90.2% and 70.0% compared with the control respectively, whereas, the differences among the treatments were not significant. TP in water column decreased with planting densities by 38.9% -57.1%, and the differences among treatments were distinct. As a function of radial oxygen releases from root, the Eh values of sediment increased by 58.6-109.4mV with the planting density compared with the control.Whereas, the pH in the 3 treatments decreased sharply during the first 20 days, then increased up to 7.20-7.34, but still lower than that of the control, which could be explained by the releases of root exudates. In addition, the growth of H. verticillata can effectively reduce the TN and TP in the sediment. It is concluded that the existence of H. verticillata can remove nutrition and improve the quality ofwater column and sediment1 However, plant density is a factor need to be considered in revegetation of degraded lakes, because excessive densitymay inhibit the growth of plants1 So harvesting at appropriate time is a necessary measure to enhance the effect of the submerged macrophyte.
Open Access
2009, 33(4): 596-602.
Abstract：
Copper sulphate treatment is widely used as a global and empirical method to remove or control phytoplanktonblooms. We tested the acute toxicity of 5 species of familiarmicroalgae and gave an urban lake copper sulfate treat in order to illuminate how the water body response to copper treat, especially the change of phytoplankton species and density of microcystins. According to OECD Alga growth inhibition test, effect of copper on 5 species of familiarmicroalgae was tested, and species of Cyanophyta showed much higher sensitivity to copper than species of Chlorophyta and Bacillariophyta. In a eutrophic urban lake, CuSO4·5H2O was used as algicide to control the water bloom caused by cyanobacterial. The copper concentration applied was 102μg/L (as copper). We investigated the lake response to copper sulfate, which showed that the transparence was substantially improved; TN and TP did not change a lot; total algal decreased just after the copper sulfate treatment, and later increased again; at the beginning of the experiment, species of Cyanophyta died and the amount sharply decreased, Bacillariophyta and Chlorophyta turned to be the preponderant species, which could be related to species sensitivity to copper, and speciesof Cyanophyta began to grow again and took the predominance few days later; density of microcystins in the water rapidly decreased to level lower than that in the treatment before, only in 4d.
Copper sulphate treatment is widely used as a global and empirical method to remove or control phytoplanktonblooms. We tested the acute toxicity of 5 species of familiarmicroalgae and gave an urban lake copper sulfate treat in order to illuminate how the water body response to copper treat, especially the change of phytoplankton species and density of microcystins. According to OECD Alga growth inhibition test, effect of copper on 5 species of familiarmicroalgae was tested, and species of Cyanophyta showed much higher sensitivity to copper than species of Chlorophyta and Bacillariophyta. In a eutrophic urban lake, CuSO4·5H2O was used as algicide to control the water bloom caused by cyanobacterial. The copper concentration applied was 102μg/L (as copper). We investigated the lake response to copper sulfate, which showed that the transparence was substantially improved; TN and TP did not change a lot; total algal decreased just after the copper sulfate treatment, and later increased again; at the beginning of the experiment, species of Cyanophyta died and the amount sharply decreased, Bacillariophyta and Chlorophyta turned to be the preponderant species, which could be related to species sensitivity to copper, and speciesof Cyanophyta began to grow again and took the predominance few days later; density of microcystins in the water rapidly decreased to level lower than that in the treatment before, only in 4d.
Open Access
2009, 33(4): 603-612.
Abstract：
Recombination activating genes (Rag) are key genes in specific immunity system of vertebrate and also used asone of the molecularmarker for analysis of vertebrate evolution. Goldfish, Carassius auratus, with strong adaptive and diseases-resistant abilities, is one of the important freshwater economic fish extensively cultivated in China. And it also appears to be an excellentmodel animal for the evolution study of fish genome for its varied ploidy and abounding genetic diversity. The goldfish Rag genes have not been cloned and the specificity of goldfish specific immunity system has not been studied yet. In the present study, goldfish Rag 1 and Rag 2 geneswere cloned by polymerase chain reaction(PCR) methods, and the temporal and spatial expression pattern of RAG-1 were examined with methods of reverse transcription-polymerase chain reaction (RT-PCR) and whole mount in situ hybridization. The total length of the genomic sequence of the goldfish Rag 1gene from the initiation codon to the stop codon is4188 bp, which composed of three exons and two introns. The length of exon 1, 2 and 3 is 308bp, 1136bp and 1748bp respectively. The length of intron 1 and 2 is 105bp and 891bp respectively. The entire open reading frame (ORF) is 3192bp long, which predicated encoding a protein of 1063 amino acids. The goldfish Rag 2 has no intron in its open reading frame, the length of the genomic sequence from the initiation codon to the stop codon is 1593bp, which predicated encoding a protein of 530 amino acids. The putative structure of RAG protein in Carassius auratus are consisted of both an N2terminal domain and a core region. Comparative analysis onthe sequences of ORFS and protein amino acid of Carassius auratus, Danio rerio, Ctenopharyngodon idella, Cyprinus carpio and Oncorhynchus mykiss revealed that both Rag 1 and Rag 2 are highly conserved in evolution. Phylogenetic tree analysis on these fish based on Rag1 ORF suggested that Carassius auratus was more closely related to Cyprinus carpio, and which based on Rag 2 ORF indicated that Carassius auratus was more closely related to Danio rerio. The second intron of the Rag 1 was also highly conserved during evolution. Transcription factor binding sites analysis on the conserved region of this intron suggested that there were some putative transcription factor binding sites in it. A common conserved area which is appeared to be the SRY and SOX5 transcription factor binding siteswas observed in all the examined fish, suggesting that the expression of Rag 1 may have some relationship with the development of gonad. Tissue-specific expression analysis by RT-PCR methods, and it revealed that Rag 1 expressed mainly in the spermary and head kidney. This observation suggested that the RAGs directed DNA recombination took place not only in immunity tissue but also in gonads. Rag.expression was first detected at the 5d post-fertilization by RT-PCR. StrongmRNA in situ hybridization signalwas detected in the thymus primordium at the 9d post-fertilization, suggesting that this period might be an active DNA recombinationstage of immunogenes in goldfish.
Recombination activating genes (Rag) are key genes in specific immunity system of vertebrate and also used asone of the molecularmarker for analysis of vertebrate evolution. Goldfish, Carassius auratus, with strong adaptive and diseases-resistant abilities, is one of the important freshwater economic fish extensively cultivated in China. And it also appears to be an excellentmodel animal for the evolution study of fish genome for its varied ploidy and abounding genetic diversity. The goldfish Rag genes have not been cloned and the specificity of goldfish specific immunity system has not been studied yet. In the present study, goldfish Rag 1 and Rag 2 geneswere cloned by polymerase chain reaction(PCR) methods, and the temporal and spatial expression pattern of RAG-1 were examined with methods of reverse transcription-polymerase chain reaction (RT-PCR) and whole mount in situ hybridization. The total length of the genomic sequence of the goldfish Rag 1gene from the initiation codon to the stop codon is4188 bp, which composed of three exons and two introns. The length of exon 1, 2 and 3 is 308bp, 1136bp and 1748bp respectively. The length of intron 1 and 2 is 105bp and 891bp respectively. The entire open reading frame (ORF) is 3192bp long, which predicated encoding a protein of 1063 amino acids. The goldfish Rag 2 has no intron in its open reading frame, the length of the genomic sequence from the initiation codon to the stop codon is 1593bp, which predicated encoding a protein of 530 amino acids. The putative structure of RAG protein in Carassius auratus are consisted of both an N2terminal domain and a core region. Comparative analysis onthe sequences of ORFS and protein amino acid of Carassius auratus, Danio rerio, Ctenopharyngodon idella, Cyprinus carpio and Oncorhynchus mykiss revealed that both Rag 1 and Rag 2 are highly conserved in evolution. Phylogenetic tree analysis on these fish based on Rag1 ORF suggested that Carassius auratus was more closely related to Cyprinus carpio, and which based on Rag 2 ORF indicated that Carassius auratus was more closely related to Danio rerio. The second intron of the Rag 1 was also highly conserved during evolution. Transcription factor binding sites analysis on the conserved region of this intron suggested that there were some putative transcription factor binding sites in it. A common conserved area which is appeared to be the SRY and SOX5 transcription factor binding siteswas observed in all the examined fish, suggesting that the expression of Rag 1 may have some relationship with the development of gonad. Tissue-specific expression analysis by RT-PCR methods, and it revealed that Rag 1 expressed mainly in the spermary and head kidney. This observation suggested that the RAGs directed DNA recombination took place not only in immunity tissue but also in gonads. Rag.expression was first detected at the 5d post-fertilization by RT-PCR. StrongmRNA in situ hybridization signalwas detected in the thymus primordium at the 9d post-fertilization, suggesting that this period might be an active DNA recombinationstage of immunogenes in goldfish.
Open Access
Abstract：
Zinc (Zn) is an essentialmicroelement for normal growth and development of plants at low concentration; how2ever, it is also an important environmental pollutant due to anthropogenic pressure as well. In the present study, Nymphoides peltatum, a rooted2floating aquatic macrophyte, was cultivated with elevated concentration of Zn (0, 5, 10, 15 and 20mg/L) for 9d respectively. The response of activities of superoxide dismutase(SOD) and peroxidase(POD), osmolytes(proline and soluble sugar) to Zn stress was investigated and Ca2+ ultrastructural distribution in leaf cells was examined with the cytochemicalmethod of calcium antimonate precipitation. The results indicated that Zn decreased SOD activity by 11. 46% -75. 22% and the inhibition action reached significant level (R = -0. 8642, p 2+ mainly distributed within intercellular space and vacuole, some calcium deposits could be randomly found in cytoplasmic matrix and nucleus under normal conditions, when different dose of Zn was added into the culture solution, and the calcium level in these compartments lowered while that in cytoplasm increased remarkably, especially bigger particles of calcium deposits appeared at the inner aspect of plasmalemma and cell nucleus, which might be attributed to the opening of the calcium channels in plasmalemma and tonoplast and the loss of activity of the Ca2+ pump, this, in turn further enhanced the calcium level of cell interior. The rise of Ca2+ level in cytoplasm and cell nucleusmaybe related to the changes of a series of physiological and biochemical processes. The dense distribution of Ca2+ in inner aspect of plasmalemma and in cell nucleusmight lead to the damage to the plant cell or the death in the end. Based on observations in the present investigation, it can be concluded that several defense systems are activated simultaneously when affected by Zn, including the induction of stress enzymes (POD), increase of synthesis or content in osmolytes (proline and soluble sugar) and changes in the distribution and content of loosely-bound Ca2+.
Zinc (Zn) is an essentialmicroelement for normal growth and development of plants at low concentration; how2ever, it is also an important environmental pollutant due to anthropogenic pressure as well. In the present study, Nymphoides peltatum, a rooted2floating aquatic macrophyte, was cultivated with elevated concentration of Zn (0, 5, 10, 15 and 20mg/L) for 9d respectively. The response of activities of superoxide dismutase(SOD) and peroxidase(POD), osmolytes(proline and soluble sugar) to Zn stress was investigated and Ca2+ ultrastructural distribution in leaf cells was examined with the cytochemicalmethod of calcium antimonate precipitation. The results indicated that Zn decreased SOD activity by 11. 46% -75. 22% and the inhibition action reached significant level (R = -0. 8642, p 2+ mainly distributed within intercellular space and vacuole, some calcium deposits could be randomly found in cytoplasmic matrix and nucleus under normal conditions, when different dose of Zn was added into the culture solution, and the calcium level in these compartments lowered while that in cytoplasm increased remarkably, especially bigger particles of calcium deposits appeared at the inner aspect of plasmalemma and cell nucleus, which might be attributed to the opening of the calcium channels in plasmalemma and tonoplast and the loss of activity of the Ca2+ pump, this, in turn further enhanced the calcium level of cell interior. The rise of Ca2+ level in cytoplasm and cell nucleusmaybe related to the changes of a series of physiological and biochemical processes. The dense distribution of Ca2+ in inner aspect of plasmalemma and in cell nucleusmight lead to the damage to the plant cell or the death in the end. Based on observations in the present investigation, it can be concluded that several defense systems are activated simultaneously when affected by Zn, including the induction of stress enzymes (POD), increase of synthesis or content in osmolytes (proline and soluble sugar) and changes in the distribution and content of loosely-bound Ca2+.
Open Access
Abstract：
Yellow pond turtle, M auremys mutica and three-striped box turtle, Cuora trifasciata, is classified to Bataguridae, M auremys and Cuora, respectively, they distribute in Southern China1 The two turtles have been artificially-propagated successfully and were cultivated in a small-scale. M auremys iversoni is a new strain nominated by Pritchard in 1991,but in 2001, two research groups leading by Parham and Wink proved that M auremys iversoni was not a species1With different methods, they found that M auremys iversoni may be the hybrid of yellow pond turtle and three2striped box turtle1 In this article, the hybrid of M. mutica (♀) ×C. trifasciata (♂) was acquired successfully, which indicated the hybrid between genus of M auremys and Cuora was feasible. But the rate of fecundation and hatching of M. mutica (♀) ×C.trifasciata (♂) were lower than M. mutica (♀) ×M. mutica (♂). The veins on carapace, the dark patch on plastron, the forepart form and origination of gular scute, the ratio between gular scute width and gular scute seam length, gular scute seam length and humeral scute seam length, femoral scute seam length and anal scute seam length, the skin color of inside of four limbs and tail abdomen of the young hybrid were different from the youngM. mutica. The growth rate of the one year old hybrid was faster than M. mutica in the same culture condition. In morphology of hybrid, the color of calvarias was thin brown-yellow, and it has two black lines behind the eyes, the abdomen of neck was yellow; the carapace was brown and its plastron was thin yellow, each scute of plastron has radiated dark patch, the skin color of inside of four limbs and tail abdomen of the hybrid were yellow-brown. The analysis ofmorphologic data within three kinds of turtles indicated that the hybrid was more closed to itsmother, M. mutica. Morphologic discriminant formula of three turtleswere obtained, discriminant analysis indicated that there were significant different among three kinds turtles1 The identification accuracy was 100% (p < 0101). The ratio between second half plastron length, gular scute width, humeral scute seam length, femoral scute seam length, respectively, and carapace length were the highest contributing rate on discriminant analysis, which could be the direct parameter in distinguishing yellow pond turtle, three-striped box turtle and their hybrid. The studywould be benefit to identification of hybrid, turtle breeding and aquaculture.
Yellow pond turtle, M auremys mutica and three-striped box turtle, Cuora trifasciata, is classified to Bataguridae, M auremys and Cuora, respectively, they distribute in Southern China1 The two turtles have been artificially-propagated successfully and were cultivated in a small-scale. M auremys iversoni is a new strain nominated by Pritchard in 1991,but in 2001, two research groups leading by Parham and Wink proved that M auremys iversoni was not a species1With different methods, they found that M auremys iversoni may be the hybrid of yellow pond turtle and three2striped box turtle1 In this article, the hybrid of M. mutica (♀) ×C. trifasciata (♂) was acquired successfully, which indicated the hybrid between genus of M auremys and Cuora was feasible. But the rate of fecundation and hatching of M. mutica (♀) ×C.trifasciata (♂) were lower than M. mutica (♀) ×M. mutica (♂). The veins on carapace, the dark patch on plastron, the forepart form and origination of gular scute, the ratio between gular scute width and gular scute seam length, gular scute seam length and humeral scute seam length, femoral scute seam length and anal scute seam length, the skin color of inside of four limbs and tail abdomen of the young hybrid were different from the youngM. mutica. The growth rate of the one year old hybrid was faster than M. mutica in the same culture condition. In morphology of hybrid, the color of calvarias was thin brown-yellow, and it has two black lines behind the eyes, the abdomen of neck was yellow; the carapace was brown and its plastron was thin yellow, each scute of plastron has radiated dark patch, the skin color of inside of four limbs and tail abdomen of the hybrid were yellow-brown. The analysis ofmorphologic data within three kinds of turtles indicated that the hybrid was more closed to itsmother, M. mutica. Morphologic discriminant formula of three turtleswere obtained, discriminant analysis indicated that there were significant different among three kinds turtles1 The identification accuracy was 100% (p < 0101). The ratio between second half plastron length, gular scute width, humeral scute seam length, femoral scute seam length, respectively, and carapace length were the highest contributing rate on discriminant analysis, which could be the direct parameter in distinguishing yellow pond turtle, three-striped box turtle and their hybrid. The studywould be benefit to identification of hybrid, turtle breeding and aquaculture.
Open Access
Abstract：
Red swamp crayfish, Procambarus clarkia, with advantagesof easy cultivation and availability, can live in various tough environments, so intrigued researchers pay attention to its ecology, toxicology, physiology and immunology.We studied an inducible cDNA encoding HSP70 in P. clarkia which would contribute to extensive researches of HSP70s and environmental stresses1 An inducible heat shock protein 70 (HSP70) cDNA was cloned from red swamp crayfish by RT-PCR and RACE, which named scHSP701 The full2length cDNA of the scHSP70 was 2271bp, consisting of a partial 5′-terminal untranslated region (UTR) of 142bp, a 3′-terminal UTR of 221bp, an open reading frame of 1902bp (ORF) and a poly (A) tail and GenBank No1 DQ3015061 The gene contained only one exon according to amplification of scHSP70 from genomic DNA1 The scHSP70 cDNA encoded a polypeptide of 635 amino acids. Based on phylogenetic analysis, the gene was clustered with inducible HSP70 familymembers from other species. The evolution relationship was consisted with traditional classification1 Semi-quantitative PCR was employed to assess the temporal expression of scHSP70 mRNA levels from heat-shock treated and unstressed crayfish1 Challenge of the red swamp crayfish with 2h heat shock resulted in dramatic increases in the expression of HSP70 mRNA levels in all tissues, heart, muscle, hemocytes, digestive gland, antennal gland, testis and intestine, among which, the highest expression was found in heart. However, under normal conditions, the expressions of HSP70 mRNA levelweremuch lower in all tissues compared to treated ones, especially in haemocytes. The upregulated mRNA expression of the HSP70 in the crayfish following heat shock indicates that scHSP70 gene is inducible. These stress proteins provide invaluable information in stress response in the crayfish.
Red swamp crayfish, Procambarus clarkia, with advantagesof easy cultivation and availability, can live in various tough environments, so intrigued researchers pay attention to its ecology, toxicology, physiology and immunology.We studied an inducible cDNA encoding HSP70 in P. clarkia which would contribute to extensive researches of HSP70s and environmental stresses1 An inducible heat shock protein 70 (HSP70) cDNA was cloned from red swamp crayfish by RT-PCR and RACE, which named scHSP701 The full2length cDNA of the scHSP70 was 2271bp, consisting of a partial 5′-terminal untranslated region (UTR) of 142bp, a 3′-terminal UTR of 221bp, an open reading frame of 1902bp (ORF) and a poly (A) tail and GenBank No1 DQ3015061 The gene contained only one exon according to amplification of scHSP70 from genomic DNA1 The scHSP70 cDNA encoded a polypeptide of 635 amino acids. Based on phylogenetic analysis, the gene was clustered with inducible HSP70 familymembers from other species. The evolution relationship was consisted with traditional classification1 Semi-quantitative PCR was employed to assess the temporal expression of scHSP70 mRNA levels from heat-shock treated and unstressed crayfish1 Challenge of the red swamp crayfish with 2h heat shock resulted in dramatic increases in the expression of HSP70 mRNA levels in all tissues, heart, muscle, hemocytes, digestive gland, antennal gland, testis and intestine, among which, the highest expression was found in heart. However, under normal conditions, the expressions of HSP70 mRNA levelweremuch lower in all tissues compared to treated ones, especially in haemocytes. The upregulated mRNA expression of the HSP70 in the crayfish following heat shock indicates that scHSP70 gene is inducible. These stress proteins provide invaluable information in stress response in the crayfish.
Open Access
Abstract：
FivematureTriplophysa bleekeri, captured in themiddle section of theQ ingyijiangR iver, were selected for art-ificial fertilization in th is study1 The fertilized eggs were released into a tank (36.0× 28.0× 11.0cm3) under the watertemperature of 9.0-1218℃. Themorphological development of embryos and larvawere described and photographed with LeicaMZ16A stereom icroscope1 30 specmi enswere sampled and observed in intervals of 30m in during embryon ic stages and 12h after hatching1 The resu lts ind icated thatmature unfertilized eggswere strongly adhesive and sphericalwith prmi -rose yellow color and contained a relatively small yolk (0.94-1.10mm in diameter). The first cleavage occurred at 4h20min after fertilization1 The blastula and gastrula stages began at 19h50m in and 27h40min, respectively1 By 64h40min after fertilization, the blastoporewas found to be almost closed. Eye pigmentwas observed at 160h30min and pectoral fin buds appeared 13h50m in later. Hatching occurred at 287h and finished at 405h30min.New ly hatched larvae usually lied on the bottom of thewater, which were 4.32mm in average total length (TL) with myomeres ranging from 36 to 38 pairs.Pigment on the body and eyes appeared clearly and pectoral fin buds were well-developed1 Thick sensory buds appeared on both sides of the head and body on the 5 dph (days post hatch ing). 3 days later, the larvae reached 6.05mm in averageTL and consumed their yolk completely. In artificially reared conditions, the larvae were fed with egg vitellus and some species of Tubifex twice a day, all specmi enswere diverted into constant temperature biochem ical incubator after 21 dph. One-chamber air bladder and two-chamber ones formed on the 30 dph and 50 dph, respectively. The larvae had 52 to 53 myomereswhen the total length reached 14105mm in TL on the 55 dph, moreover, all fin rays reached the same fixed number of adult fish and 7 to 8 dark-brown speckle bands had appeared on the body sides. Yolk sac volumes of the larvae decreased at the average ratio of 0.027mm3/d. Growth in length and bodymorphometrics varied during d ifferent developmental stages1 The proportion of post-anal length to total length increased gradually from 31% at the beginning and it stabilized at about 42% finally.
FivematureTriplophysa bleekeri, captured in themiddle section of theQ ingyijiangR iver, were selected for art-ificial fertilization in th is study1 The fertilized eggs were released into a tank (36.0× 28.0× 11.0cm3) under the watertemperature of 9.0-1218℃. Themorphological development of embryos and larvawere described and photographed with LeicaMZ16A stereom icroscope1 30 specmi enswere sampled and observed in intervals of 30m in during embryon ic stages and 12h after hatching1 The resu lts ind icated thatmature unfertilized eggswere strongly adhesive and sphericalwith prmi -rose yellow color and contained a relatively small yolk (0.94-1.10mm in diameter). The first cleavage occurred at 4h20min after fertilization1 The blastula and gastrula stages began at 19h50m in and 27h40min, respectively1 By 64h40min after fertilization, the blastoporewas found to be almost closed. Eye pigmentwas observed at 160h30min and pectoral fin buds appeared 13h50m in later. Hatching occurred at 287h and finished at 405h30min.New ly hatched larvae usually lied on the bottom of thewater, which were 4.32mm in average total length (TL) with myomeres ranging from 36 to 38 pairs.Pigment on the body and eyes appeared clearly and pectoral fin buds were well-developed1 Thick sensory buds appeared on both sides of the head and body on the 5 dph (days post hatch ing). 3 days later, the larvae reached 6.05mm in averageTL and consumed their yolk completely. In artificially reared conditions, the larvae were fed with egg vitellus and some species of Tubifex twice a day, all specmi enswere diverted into constant temperature biochem ical incubator after 21 dph. One-chamber air bladder and two-chamber ones formed on the 30 dph and 50 dph, respectively. The larvae had 52 to 53 myomereswhen the total length reached 14105mm in TL on the 55 dph, moreover, all fin rays reached the same fixed number of adult fish and 7 to 8 dark-brown speckle bands had appeared on the body sides. Yolk sac volumes of the larvae decreased at the average ratio of 0.027mm3/d. Growth in length and bodymorphometrics varied during d ifferent developmental stages1 The proportion of post-anal length to total length increased gradually from 31% at the beginning and it stabilized at about 42% finally.
Open Access
2009, 33(4): 643-648.
Abstract：
Restoration of submerged vegetation is the key step of restoration of aquatic ecosystem in eutrophic lakes. The seed bank was strongly destroyed in many eutrophic lakes of China, it is necessary to get plenty of seedlings for restoration of submerged vegetation because of the difficulty of getting enough macrophyte seeds. Usually, seedlings of submerged macrophytes have to be obtained from otherwater bodies. Transplantation may destroy the source vegetation and encounter shortage of seedlings in case of lack of vegetation in nearby water bodies. The technique of artificial seeds is a promising method to provide a large number of seedlings in a short time without limitation of season, long distant transportation and harm to the naturalmacrophyte community. In order to establish the method for the preparation of artificial seeds of submerged macrophytes, a common submerged macrophte Potamogeton crispus L. was selected as experimental material1 In this study, the artificial seed of P. crispus was obtained by using node segments as explant, budswere induced in induction medium1 The node segmentswithbuds of P. crispus swere encapsulated with sodium alginate and calcium chloride to form artificial seeds. The effects of hormone types and concentration in capsule, temperature, light intensity, concentration of nitrogen and phosphorus, sediment types on the germination and conversion of artificial seeds of P. crispus were investigated. An experiment of germination and conversion of the artificial seeds in lake was also conducted. The hormones supplemented in the capsules could promote the germination of artificial seeds1 The result showed that the germination and conversion rates of artificial seeds, which embedded in IBA 1.0 mg/L and 6-BA 0.5 mg/L, were 80% and 20% respectively in autoclaved tap water1 No significant effect of temperature was found on the germination and conversion in range of 15-25℃. Similarly nitrogen and phosphorus caused no significant change on the germination and conversion of artificial seeds of P. crispus. Light intensity affected the germination and conversion significantly. Higher light intensity favored the germination of artificial seeds1 The germination and conversion rates of the artificial seeds reached to 67.8% and 35.6% respectively at light intensity of 40μmol/m 2·s1 Sediment types also affected the germination significantly1 Sandy soil was better than sandstone and silt to support the germination1 The germination rate of artificial seedsof P. crispus was 60% on the sandy soil, which was higher than that in sandstone and silt sediments1 To test the feasibility of artificial seeds of P. crispus in eutrophic lakes, a trial experimentwas carried out in the EastLake which is a hyper-eutrophic lake in Wuhan, Hubei the germination and conversion rates of artificial seeds of P1 crispus were 28% and 15% underwater depth of 0.6 m, and 27% and 12% underwater depth of 1.2 m, respectively. The results showed that the artificial seed of P. crispus was applicable in restoration of aquatic vegetation in place of plant transplantation.
Restoration of submerged vegetation is the key step of restoration of aquatic ecosystem in eutrophic lakes. The seed bank was strongly destroyed in many eutrophic lakes of China, it is necessary to get plenty of seedlings for restoration of submerged vegetation because of the difficulty of getting enough macrophyte seeds. Usually, seedlings of submerged macrophytes have to be obtained from otherwater bodies. Transplantation may destroy the source vegetation and encounter shortage of seedlings in case of lack of vegetation in nearby water bodies. The technique of artificial seeds is a promising method to provide a large number of seedlings in a short time without limitation of season, long distant transportation and harm to the naturalmacrophyte community. In order to establish the method for the preparation of artificial seeds of submerged macrophytes, a common submerged macrophte Potamogeton crispus L. was selected as experimental material1 In this study, the artificial seed of P. crispus was obtained by using node segments as explant, budswere induced in induction medium1 The node segmentswithbuds of P. crispus swere encapsulated with sodium alginate and calcium chloride to form artificial seeds. The effects of hormone types and concentration in capsule, temperature, light intensity, concentration of nitrogen and phosphorus, sediment types on the germination and conversion of artificial seeds of P. crispus were investigated. An experiment of germination and conversion of the artificial seeds in lake was also conducted. The hormones supplemented in the capsules could promote the germination of artificial seeds1 The result showed that the germination and conversion rates of artificial seeds, which embedded in IBA 1.0 mg/L and 6-BA 0.5 mg/L, were 80% and 20% respectively in autoclaved tap water1 No significant effect of temperature was found on the germination and conversion in range of 15-25℃. Similarly nitrogen and phosphorus caused no significant change on the germination and conversion of artificial seeds of P. crispus. Light intensity affected the germination and conversion significantly. Higher light intensity favored the germination of artificial seeds1 The germination and conversion rates of the artificial seeds reached to 67.8% and 35.6% respectively at light intensity of 40μmol/m 2·s1 Sediment types also affected the germination significantly1 Sandy soil was better than sandstone and silt to support the germination1 The germination rate of artificial seedsof P. crispus was 60% on the sandy soil, which was higher than that in sandstone and silt sediments1 To test the feasibility of artificial seeds of P. crispus in eutrophic lakes, a trial experimentwas carried out in the EastLake which is a hyper-eutrophic lake in Wuhan, Hubei the germination and conversion rates of artificial seeds of P1 crispus were 28% and 15% underwater depth of 0.6 m, and 27% and 12% underwater depth of 1.2 m, respectively. The results showed that the artificial seed of P. crispus was applicable in restoration of aquatic vegetation in place of plant transplantation.
Open Access
Abstract：
Genetic homogeneity is the basic demand for an inbred strain of laboratory animal, which could be detected in multi-levels, includingmorphology, cytogenetics, biochemistry, immunogenetics, molecular genetics and so on1 Biochemical markers and skin grafting were recommended methods for genetic quality control of mammalian animals in the national standard GB14923-2001. However, no prescriptive methods were destined for monitoring genetic quality of aquatic laboratory animals1 Gobiocypris rarus is an endemic cyprinid fish in China, distributed only in Sichuan Province1 Because this species hasmany attractive attributes, including sensitivity to chemicals, small size, eurythermal, easily to be cared in laboratory, short life cycle (about 4 months) and so on, it has been widely used in many researches of fish pathology, genetics, toxicology, embryology, and physiology in China1 An inbred strain of Gobiocypris rarus, named HAN strain, has been established by brother-sistermating to the 23rd generation in the laboratory since 1990. In order to investigate the genetic background of the HAN strain and to monitor its genetic quality, we examined the inbred strain on external morphometric and meristic characters, skeletal morphometrics, survival of scale transplantation, electropherogram of isozymes andmicrosatellite polymorphism. The present study was a part of these series works on the examination of molecular genetic homogeneity. A total of 17 microsatellite markerswere used to analyze on 30 individuals of F22, 20 individuals of F20 ofthe HAN strain in contrastwith 30 individualsofwild type which were caught in Hanyuan County in 2006. All the 17 microsatellite markers exhibited to be polymorphic in wild populations, yet only six of them were polymorphic in F20 and four polymorphic in F22. Overall 64 alleleswere detected in the wild population, and the number of alleles per locus rangedfrom 2 to 6. But in HAN, only 1 or 2 alleles could be detected in each locus, while totally 26 and 21 alleleswere found in F20 and F22, respectively1 The average homozygosities of these microsatellite loci were 91.96%, 86.18% and 46.84% in F22, F20 and wild population, respectively. The average heterozygositywas 015744 in wild population, significantly higher than those of F22 and F20, which showed its high levels of genetic diversity. The average polymorphism information content was 0.5252, 0.3838 and 0.3837 in wild population, F20 and F22, respectively. Therefore, in contrast to wild population, the high homozygosity and low heterozygosity were found in inbred HAN strain1 Among allpopulations, the genetic similarity index between F20 and F22 was the largestone, which showed the closest genetic distance and the nearest relationship between them. The genetic distance between wild population and F20 was larger than one between F20 and F22, and smaller than one between wild population and F221 On the whole, the present study indicated that genetic diversity of inbred strain wasmuch lower than wild population, and high genetic purity resulted from long-time inbreeding was existed in HAN strain. Microsatellite markers were sensitive and effective methods for monitoring genetic quality of laboratory fish. The HAN strain maintained by brother-sister mating should be periodicallymonitored by microsatellite markers for the unpurified loci needed to be homozygosis.
Genetic homogeneity is the basic demand for an inbred strain of laboratory animal, which could be detected in multi-levels, includingmorphology, cytogenetics, biochemistry, immunogenetics, molecular genetics and so on1 Biochemical markers and skin grafting were recommended methods for genetic quality control of mammalian animals in the national standard GB14923-2001. However, no prescriptive methods were destined for monitoring genetic quality of aquatic laboratory animals1 Gobiocypris rarus is an endemic cyprinid fish in China, distributed only in Sichuan Province1 Because this species hasmany attractive attributes, including sensitivity to chemicals, small size, eurythermal, easily to be cared in laboratory, short life cycle (about 4 months) and so on, it has been widely used in many researches of fish pathology, genetics, toxicology, embryology, and physiology in China1 An inbred strain of Gobiocypris rarus, named HAN strain, has been established by brother-sistermating to the 23rd generation in the laboratory since 1990. In order to investigate the genetic background of the HAN strain and to monitor its genetic quality, we examined the inbred strain on external morphometric and meristic characters, skeletal morphometrics, survival of scale transplantation, electropherogram of isozymes andmicrosatellite polymorphism. The present study was a part of these series works on the examination of molecular genetic homogeneity. A total of 17 microsatellite markerswere used to analyze on 30 individuals of F22, 20 individuals of F20 ofthe HAN strain in contrastwith 30 individualsofwild type which were caught in Hanyuan County in 2006. All the 17 microsatellite markers exhibited to be polymorphic in wild populations, yet only six of them were polymorphic in F20 and four polymorphic in F22. Overall 64 alleleswere detected in the wild population, and the number of alleles per locus rangedfrom 2 to 6. But in HAN, only 1 or 2 alleles could be detected in each locus, while totally 26 and 21 alleleswere found in F20 and F22, respectively1 The average homozygosities of these microsatellite loci were 91.96%, 86.18% and 46.84% in F22, F20 and wild population, respectively. The average heterozygositywas 015744 in wild population, significantly higher than those of F22 and F20, which showed its high levels of genetic diversity. The average polymorphism information content was 0.5252, 0.3838 and 0.3837 in wild population, F20 and F22, respectively. Therefore, in contrast to wild population, the high homozygosity and low heterozygosity were found in inbred HAN strain1 Among allpopulations, the genetic similarity index between F20 and F22 was the largestone, which showed the closest genetic distance and the nearest relationship between them. The genetic distance between wild population and F20 was larger than one between F20 and F22, and smaller than one between wild population and F221 On the whole, the present study indicated that genetic diversity of inbred strain wasmuch lower than wild population, and high genetic purity resulted from long-time inbreeding was existed in HAN strain. Microsatellite markers were sensitive and effective methods for monitoring genetic quality of laboratory fish. The HAN strain maintained by brother-sister mating should be periodicallymonitored by microsatellite markers for the unpurified loci needed to be homozygosis.
Open Access
Abstract：
The pufferfishes of the genus Takifugu are East Asian fish, mainly distribute along the coastal region in western part of the Sea of Japan and the East China. This genus is attached more and more importance to researchers, for Takifugu rubripes, which isone species in it, has been a new model fish in the post-genomic era. The detailsof the phylogenetic relationships within the genus remain unresolved. In the present paper, mitochondrial D-loop sequences of 11 species of the genus Takifugu were determined and analyzed to test the present phylogenetic hypotheses1 The sequence saturation analysis was inferred from the shape of the trend line, which indicated that the sequence was unsaturated and could be used in the following phylogenetic analysis. After alignment, the sequence compositions and variations were analyzed by using MEGA 3 software. There were 841 sites, amongwhich 395 siteswere variable, and 267 were informative1 There was significant difference in base compositional bias between the ingroup and the outgroup species1 The uncorrected p-distance matrix obtained from the analysisof the alignment of all D-loop sequences showed that the relationships among the different specieswere closely. Neighbor-joining, Maximum Parsimony, Maximum Likelihood and Bayesian methodswere employed for phylogenetics analysis, respectively. Due to the SH test about the phylogeny hypothesis, we chose the Bayesian tree as our best tree in this paper. The Bayesian tree has described a more clearly phylogeny and the analysis also has pointed out the basal species in the genus. The results indicate that the genus form a monophyletic groups, with the sister group consisted by T. oblongus and T. alboplumbeus is the basal group of the genus1 Our results also show some confusion about the taxonomy in the genus, according to the data and combined analysis with the morphological characters, we suppose some species are in fact synonymous in this genus, which suggest that the taxonomy should be clarified based on both molecular and morphological data in the future.
The pufferfishes of the genus Takifugu are East Asian fish, mainly distribute along the coastal region in western part of the Sea of Japan and the East China. This genus is attached more and more importance to researchers, for Takifugu rubripes, which isone species in it, has been a new model fish in the post-genomic era. The detailsof the phylogenetic relationships within the genus remain unresolved. In the present paper, mitochondrial D-loop sequences of 11 species of the genus Takifugu were determined and analyzed to test the present phylogenetic hypotheses1 The sequence saturation analysis was inferred from the shape of the trend line, which indicated that the sequence was unsaturated and could be used in the following phylogenetic analysis. After alignment, the sequence compositions and variations were analyzed by using MEGA 3 software. There were 841 sites, amongwhich 395 siteswere variable, and 267 were informative1 There was significant difference in base compositional bias between the ingroup and the outgroup species1 The uncorrected p-distance matrix obtained from the analysisof the alignment of all D-loop sequences showed that the relationships among the different specieswere closely. Neighbor-joining, Maximum Parsimony, Maximum Likelihood and Bayesian methodswere employed for phylogenetics analysis, respectively. Due to the SH test about the phylogeny hypothesis, we chose the Bayesian tree as our best tree in this paper. The Bayesian tree has described a more clearly phylogeny and the analysis also has pointed out the basal species in the genus. The results indicate that the genus form a monophyletic groups, with the sister group consisted by T. oblongus and T. alboplumbeus is the basal group of the genus1 Our results also show some confusion about the taxonomy in the genus, according to the data and combined analysis with the morphological characters, we suppose some species are in fact synonymous in this genus, which suggest that the taxonomy should be clarified based on both molecular and morphological data in the future.
Open Access
Abstract：
Based on the data of the shrimp resources sampled by single trawler as investigation boat in 18 stations in the offshore waters of the Mid-Southern East China Sea (26°00′N-28°30′N, 121°00′E-126°00′E) in May, August, November, 2006 and February, 2007, total catch from each trawlerwas counted and identified to species in taxonomy, and the spatial variation of the shrimp species composition, index of relative importance (IRI),the diversity and similar characteristics of the community structure were analyzed. 32 species of shrimp were caught in this survey, which belonged to 22 families under 11 genera1 Comparison of the amounts of various species in different seasons: there are 22 species in the autumn which are the most; 20 species in winter, 17 and 18 species in the spring and the summer respectively. According to the standard of index of relative importance (IRI) (the specieswith IRI above 1000 were regarded as the dominant species in this paper), there were 10 dominant species: M etapenaeopsis longirostris, M etapenaeopsis dalei, Solenocera alticarinata, Plesionika izum iae, Ibacus novemdentatu, Parapenaeus fissuroides, Solenocera koelbeli, Solenocera crassicornis, Parapenaeopsis hardwickii and Solenocera crassicornis, and 5 of them were major dominant specieswhich were M etapenaeopsis long irostris, M etapenaeopsis dalei, Plesionika izum iae, Parapenaeus fissuroides and Parapenaeopsis hardwickii. Defined the ones with IRI values ranging from 100 to 1000 as common species, we got 7: M etapenaeopsis barbata, Penaeus japonicus, Plesionika dentirostris, Palaemon gravieri, Alpheus japonicus, Parapandalus spinipes and Sicyonia cristata. The abundance of the dominant species was varied with seasons. For example, 5 were in May: M etapenaeopsis longirostris, M etapenaeopsis dalei, Parapenaeopsis hardwickii, Solenocera alticarinata and Plesionika izum iae, 89.15% of the total catch and 92.14% of the total individuals. In August, there were 7 dominant species: M etapenaeopsis dalei, Plesionika izum iae, M etapenaeopsis longirostris, Parapenaeus fissuroide, Solenocera crassicornis, Ibacus novemdentatus and Solenocera alticarinata, 91.82% of the total catch and 95.05% of the total individuals. In November, the number of dominant species increased to 8: M etapenaeopsis longirostris, Plesionika izum iae, Parapenaeus fissuroides, M etapenaeopsis dalei, Solenocera crassicornis, Ibacus novemdentatus, Solenocera koelbeli and Solenocera alticarinata, occupying 95.31% and 97.56% of the total catch individuals, respectively. In February, the number reduced to 5: M etapenaeopsis longirostris, Parapenaeus fissuroides, M etapenaeopsis dalei, Solenocera koelbeli and Plesionika izum iae, 88.76% and 94.93% respectively. Based on their adaptability to habitats, all recorded species of shrimpswere categorized into the hyperthermal and hysaline community in the Mid-Southern EastChina Sea. The stationswith high abundance were mainly located in the west of the 120m isobaths, and gradually lower toward the autumn to winter, while it reached the lowest in winter1Margalef index (D) and Shannon-Wienner index (H′) were higher in summer and autumn than those in winter and spring, Pielou’s evenness index (J′) in the offshorewatersof theMid2Southern East China Seawas stable through every season. The result indicated that the diversity index west of the 120m isobaths was higher than in the east. By hierarchical cluster analysis and non-metric multidimensional scaling (NMDS) assisted analyzing, the types of shrimp assemblage determined by influential factor such as aquatic system, watermass and salinity etc. in the East China Sea in spring were also discussed in the article, two main assemblages were identified in the offshore waters of the Mid-Southern East China Sea, which were deeper costal shrimp assemblage and out shelf sea shrimp assemblage.
Based on the data of the shrimp resources sampled by single trawler as investigation boat in 18 stations in the offshore waters of the Mid-Southern East China Sea (26°00′N-28°30′N, 121°00′E-126°00′E) in May, August, November, 2006 and February, 2007, total catch from each trawlerwas counted and identified to species in taxonomy, and the spatial variation of the shrimp species composition, index of relative importance (IRI),the diversity and similar characteristics of the community structure were analyzed. 32 species of shrimp were caught in this survey, which belonged to 22 families under 11 genera1 Comparison of the amounts of various species in different seasons: there are 22 species in the autumn which are the most; 20 species in winter, 17 and 18 species in the spring and the summer respectively. According to the standard of index of relative importance (IRI) (the specieswith IRI above 1000 were regarded as the dominant species in this paper), there were 10 dominant species: M etapenaeopsis longirostris, M etapenaeopsis dalei, Solenocera alticarinata, Plesionika izum iae, Ibacus novemdentatu, Parapenaeus fissuroides, Solenocera koelbeli, Solenocera crassicornis, Parapenaeopsis hardwickii and Solenocera crassicornis, and 5 of them were major dominant specieswhich were M etapenaeopsis long irostris, M etapenaeopsis dalei, Plesionika izum iae, Parapenaeus fissuroides and Parapenaeopsis hardwickii. Defined the ones with IRI values ranging from 100 to 1000 as common species, we got 7: M etapenaeopsis barbata, Penaeus japonicus, Plesionika dentirostris, Palaemon gravieri, Alpheus japonicus, Parapandalus spinipes and Sicyonia cristata. The abundance of the dominant species was varied with seasons. For example, 5 were in May: M etapenaeopsis longirostris, M etapenaeopsis dalei, Parapenaeopsis hardwickii, Solenocera alticarinata and Plesionika izum iae, 89.15% of the total catch and 92.14% of the total individuals. In August, there were 7 dominant species: M etapenaeopsis dalei, Plesionika izum iae, M etapenaeopsis longirostris, Parapenaeus fissuroide, Solenocera crassicornis, Ibacus novemdentatus and Solenocera alticarinata, 91.82% of the total catch and 95.05% of the total individuals. In November, the number of dominant species increased to 8: M etapenaeopsis longirostris, Plesionika izum iae, Parapenaeus fissuroides, M etapenaeopsis dalei, Solenocera crassicornis, Ibacus novemdentatus, Solenocera koelbeli and Solenocera alticarinata, occupying 95.31% and 97.56% of the total catch individuals, respectively. In February, the number reduced to 5: M etapenaeopsis longirostris, Parapenaeus fissuroides, M etapenaeopsis dalei, Solenocera koelbeli and Plesionika izum iae, 88.76% and 94.93% respectively. Based on their adaptability to habitats, all recorded species of shrimpswere categorized into the hyperthermal and hysaline community in the Mid-Southern EastChina Sea. The stationswith high abundance were mainly located in the west of the 120m isobaths, and gradually lower toward the autumn to winter, while it reached the lowest in winter1Margalef index (D) and Shannon-Wienner index (H′) were higher in summer and autumn than those in winter and spring, Pielou’s evenness index (J′) in the offshorewatersof theMid2Southern East China Seawas stable through every season. The result indicated that the diversity index west of the 120m isobaths was higher than in the east. By hierarchical cluster analysis and non-metric multidimensional scaling (NMDS) assisted analyzing, the types of shrimp assemblage determined by influential factor such as aquatic system, watermass and salinity etc. in the East China Sea in spring were also discussed in the article, two main assemblages were identified in the offshore waters of the Mid-Southern East China Sea, which were deeper costal shrimp assemblage and out shelf sea shrimp assemblage.
Open Access
2009, 33(4): 674-681.
Abstract：
The objective of th is studywas to investigate the dietary protein requirement of the juvenile Spinibarbus sinensis and determine effects of dietary protein levels on feed intake, growth and nutrition utilization. W hite fish mealwas used as the dietary protein source, and six isocaloric expermi ental diets were formulated to contain d ifferent protein levels of 20.49%, 26.48%, 34.20%, 41.02%, 49.94% and 55.86% (referred to as D1, D2, D3, D4, D5 and D6 respectively). Each treatment had four replicates and 12 fish (in itialweight of (10.36 ± 1.40) g (mean ± S.D.)) of each replicatewere reared in a circulated filtered system for 10 weeks at (27.5 ± 0.5) e in a circu lated filtered rearing system. Fish were hand fed to satiation once daily at 18: 00. Feceswere collected from the second week by siphoning and washed mi med iately everyday. A sample of 9 fish at the start of feeding expermi ent and 4 fish per group at the end of expermi ent were sampled and stored frozen at-26℃ for proxmi ate composition analysis1 Fish were weighted individually after 48h starvation at the end of the expermi ent. The results showed that as dietary protein increased, the feeding rate of drymatter (FRdm) decreased gradually from D1 toD4 firstly, and then leveled off1However, a positive correlation between the feeding rate of protein (FRp) and die-tary protein levels was found (r= 0.982,ppSGRw), specific growth rates of energy (SGRe) and feed efficiency (FE) were significantly increased from D1 up toD4 (pSGRw, SGRe and FE reached a plateau and did not d iffer significan-tly among D4, D5 and D6. Protein efficiency ratio (PER) decreased from 178.23 to 116.60% as dietary protein level increased from D1 to D6. Values of protein productive values (PPV) had a smi ilar trend like PER, which decreased from 23.92 to 18.62% as dietary protein levels increased from D1 to D6. Energy productive values (EPV) significantly in-creased from (20.05 ± 0.39) to (28.87 ± 0.81)% as dietary protein increased from D1 to D4, then decreased to (23.49 ± 2.00)% for D6. Based on the broken linemodels between SGRw, SGRe, FE and d ietary protein levels, the optmi al d ietary protein requirement for juvenileS. sinensis was estmi ated to be 39.6% -42.2% when wh ite fish mealwas the sole protein source and the dietary energy valuewas 15.71M J/kg. This optmi um d ietary protein level for juvenileS. sinensis is higher than some other omnivorous fishes. It suggested that the food hab it of juven ileS. sinensis preferring an-imal plankton and zooplankton make it need more dietary protein for growth1 Smi ultaneously, the growth rate of juvenile S. sinensis is slower than those of some other fish species, which could be due to its small diet intake ratio and low apparent digestibility of dietary protein.
The objective of th is studywas to investigate the dietary protein requirement of the juvenile Spinibarbus sinensis and determine effects of dietary protein levels on feed intake, growth and nutrition utilization. W hite fish mealwas used as the dietary protein source, and six isocaloric expermi ental diets were formulated to contain d ifferent protein levels of 20.49%, 26.48%, 34.20%, 41.02%, 49.94% and 55.86% (referred to as D1, D2, D3, D4, D5 and D6 respectively). Each treatment had four replicates and 12 fish (in itialweight of (10.36 ± 1.40) g (mean ± S.D.)) of each replicatewere reared in a circulated filtered system for 10 weeks at (27.5 ± 0.5) e in a circu lated filtered rearing system. Fish were hand fed to satiation once daily at 18: 00. Feceswere collected from the second week by siphoning and washed mi med iately everyday. A sample of 9 fish at the start of feeding expermi ent and 4 fish per group at the end of expermi ent were sampled and stored frozen at-26℃ for proxmi ate composition analysis1 Fish were weighted individually after 48h starvation at the end of the expermi ent. The results showed that as dietary protein increased, the feeding rate of drymatter (FRdm) decreased gradually from D1 toD4 firstly, and then leveled off1However, a positive correlation between the feeding rate of protein (FRp) and die-tary protein levels was found (r= 0.982,ppSGRw), specific growth rates of energy (SGRe) and feed efficiency (FE) were significantly increased from D1 up toD4 (pSGRw, SGRe and FE reached a plateau and did not d iffer significan-tly among D4, D5 and D6. Protein efficiency ratio (PER) decreased from 178.23 to 116.60% as dietary protein level increased from D1 to D6. Values of protein productive values (PPV) had a smi ilar trend like PER, which decreased from 23.92 to 18.62% as dietary protein levels increased from D1 to D6. Energy productive values (EPV) significantly in-creased from (20.05 ± 0.39) to (28.87 ± 0.81)% as dietary protein increased from D1 to D4, then decreased to (23.49 ± 2.00)% for D6. Based on the broken linemodels between SGRw, SGRe, FE and d ietary protein levels, the optmi al d ietary protein requirement for juvenileS. sinensis was estmi ated to be 39.6% -42.2% when wh ite fish mealwas the sole protein source and the dietary energy valuewas 15.71M J/kg. This optmi um d ietary protein level for juvenileS. sinensis is higher than some other omnivorous fishes. It suggested that the food hab it of juven ileS. sinensis preferring an-imal plankton and zooplankton make it need more dietary protein for growth1 Smi ultaneously, the growth rate of juvenile S. sinensis is slower than those of some other fish species, which could be due to its small diet intake ratio and low apparent digestibility of dietary protein.
Open Access
Abstract：
Vitamin C is an essential micro-nutrient formost fish and plays an important role in immunity and physiology. The deficiency of dietary vitamin C can result in the damage on fish. The study on the deficiency symptom and the sensitive indicator of vitamin C could provide useful information for fish feed industry1 This experimentwas conducted to investigate the effects of dietaryVitamin C levels on growth performance, immune and physiological responses in Chinese longsnout catfish (Leiocassis longirostris G黱ther), which is an high value aquaculture fish in China. Three practical diets containing 38, 364 and 630mg/kg vitamin C were fed to Chinese longsnout catfish (23119 ?158g) for 8 months1 Vitamin C was used in the form of L-ascorbyl-2-polyphosphate1 The results indicated that the Chinese longsnout catfish in 38mg/kg vitamin C groups showed typical vitamin C deficiency symptom: skin color turning darker, spinal deformities and scoliosis, erosion of fins, anaemia1 SGR and the serum lysozyme activities decreased significantly (p p p >0105). The inductive HSP70 in liver was not detected by western2blotting in all groups. In conclusion, serum cortisol and hepatic HSP70 were not the sensitive indicators for vitamin C deficiency symptom, but the serum lysozyme, hepatic SOD activity, hepatic MDA content and the haematological index (red blood cell number and hemoglobin content) were the more reliable makers to indicate the physiological status in Chinese longsnout catfish.
Vitamin C is an essential micro-nutrient formost fish and plays an important role in immunity and physiology. The deficiency of dietary vitamin C can result in the damage on fish. The study on the deficiency symptom and the sensitive indicator of vitamin C could provide useful information for fish feed industry1 This experimentwas conducted to investigate the effects of dietaryVitamin C levels on growth performance, immune and physiological responses in Chinese longsnout catfish (Leiocassis longirostris G黱ther), which is an high value aquaculture fish in China. Three practical diets containing 38, 364 and 630mg/kg vitamin C were fed to Chinese longsnout catfish (23119 ?158g) for 8 months1 Vitamin C was used in the form of L-ascorbyl-2-polyphosphate1 The results indicated that the Chinese longsnout catfish in 38mg/kg vitamin C groups showed typical vitamin C deficiency symptom: skin color turning darker, spinal deformities and scoliosis, erosion of fins, anaemia1 SGR and the serum lysozyme activities decreased significantly (p p p >0105). The inductive HSP70 in liver was not detected by western2blotting in all groups. In conclusion, serum cortisol and hepatic HSP70 were not the sensitive indicators for vitamin C deficiency symptom, but the serum lysozyme, hepatic SOD activity, hepatic MDA content and the haematological index (red blood cell number and hemoglobin content) were the more reliable makers to indicate the physiological status in Chinese longsnout catfish.
Open Access
2009, 33(4): 690-695.
Abstract：
Studies about genetic diversity of crucian carp (Carassius auratus) have been executed formany years. However, the samples usually come from the area of Heilong River in northeast, Yangtze River and Yellow River in the middle part of China, rarely from the district of SinkiangDistrict in northwest of China. This study aim at accumulating evidences for realizing genetic diversity and finding some characteristic marks of genetic diversity of crucian carp in the district of Sinkiang District in northwest of China. The sampled crucian carps (Carassius auratus) captured with townet from Yili River of Sinkiang district. Their sex was identified according to the gland at the anatomical level. DNA content of blood corpuscle was mensurated with Phoenix Flow Systems after blood corpuscle was dyed with propidium iodide (PI) solution. Transferrin (Tf) in blood serum was measured with non-denatualization polyacrylamide gel electrophoresis. Itwas staimed with coommassie brilliant blue G22501 The result indicates that there are both ofmale and female among the crucian carpgroups. DNA content of blood corpuscle of crucian carp is about 1153 times of the color diploid crucian carp (actual 5.315 ±0.215pg/nucleus: 3.475 ±0.079 pg/nucleus, respectively). The quantity is matching with that of the gibel carp (Carassius auratus gibelio Bloch). Nine phenotype of Tf have been discovered among those crucian carps, controlled by seven alleles1 Its genic frequency is Tfa0.063、Tfb0.063、Tff0.095、Tfg0.169、Tfc0.174、Tfe0.175 and Tfd0.270. Genotype frequency is Tfde0.13, Tfcd0.043, Tfce0.13, Tfdf0.13, Tfcdg0.26, Tfcdf 0.043, Tfdef0.087, Tfabeg0.13, Tfabdg0.043, respectively, presenting a very plentiful genetic diversity1 These indicate that there are two kinds of reproductive modes of sexual reproduction and clonal reproduction of gynogenesis among this group of Crucian Carp (Carassius auratus) from Yili River of Sinkiang District. The crucian carps (Carassius auratus) are silver Crucian carp (Carassius auratus gibelio Bloch). Diversity in reproductive modesmay play an important role in ecological adaptation of crucian carps. They may have evolved over several undiscovered event in history.
Studies about genetic diversity of crucian carp (Carassius auratus) have been executed formany years. However, the samples usually come from the area of Heilong River in northeast, Yangtze River and Yellow River in the middle part of China, rarely from the district of SinkiangDistrict in northwest of China. This study aim at accumulating evidences for realizing genetic diversity and finding some characteristic marks of genetic diversity of crucian carp in the district of Sinkiang District in northwest of China. The sampled crucian carps (Carassius auratus) captured with townet from Yili River of Sinkiang district. Their sex was identified according to the gland at the anatomical level. DNA content of blood corpuscle was mensurated with Phoenix Flow Systems after blood corpuscle was dyed with propidium iodide (PI) solution. Transferrin (Tf) in blood serum was measured with non-denatualization polyacrylamide gel electrophoresis. Itwas staimed with coommassie brilliant blue G22501 The result indicates that there are both ofmale and female among the crucian carpgroups. DNA content of blood corpuscle of crucian carp is about 1153 times of the color diploid crucian carp (actual 5.315 ±0.215pg/nucleus: 3.475 ±0.079 pg/nucleus, respectively). The quantity is matching with that of the gibel carp (Carassius auratus gibelio Bloch). Nine phenotype of Tf have been discovered among those crucian carps, controlled by seven alleles1 Its genic frequency is Tfa0.063、Tfb0.063、Tff0.095、Tfg0.169、Tfc0.174、Tfe0.175 and Tfd0.270. Genotype frequency is Tfde0.13, Tfcd0.043, Tfce0.13, Tfdf0.13, Tfcdg0.26, Tfcdf 0.043, Tfdef0.087, Tfabeg0.13, Tfabdg0.043, respectively, presenting a very plentiful genetic diversity1 These indicate that there are two kinds of reproductive modes of sexual reproduction and clonal reproduction of gynogenesis among this group of Crucian Carp (Carassius auratus) from Yili River of Sinkiang District. The crucian carps (Carassius auratus) are silver Crucian carp (Carassius auratus gibelio Bloch). Diversity in reproductive modesmay play an important role in ecological adaptation of crucian carps. They may have evolved over several undiscovered event in history.
Open Access
Abstract：
The effectsof ionic liquid 1-hexyl-3-methylimidazolium ([C6mim ]Br), with the concentrationsof 0, 1, 5, 10, 15 and 20 mg/L and exposed for the 24, 48, 72 and 96h respectively, on glutathione (GSH) and the enzymes in glutathione metabolism of Scenedesmus obliquus such as glutathione peroxidase (GPX), glutathione S-transferases (GST) and glutathione reductase (GR) were studied in the present study1 The results indicated that the GSH contents decreased with the concentration of [C6mim ]Br increasing at the 24, 48 and 72h, but it did not change when [C6mim ]Br = 1mg/L. The GSH contentswere similar to or lower than that of the control level at the 96h. The activities of GPX and GST increased markedly before 72h except for the activity of GST at the highest concentration (20 mg/L), but they both decreased to the control level at the 96h1 The activities of GR increased at the concentration of 1 mg/L and then decreased with the concentration increasing at the 24h, increased to the control level at the 48h, and then reached its peak at the 72h (when [C6mim ]Br≥10 mg/L the GR activities exceeded the control level), but at the 96h, it decreased markedly even weaker than the control level. GR was the enzyme that limited the reaction velocity in the system of glutathione cycle and the GST was the most active and sensitive enzyme. It could be used as sensitive biomarkers under the stress induced by [C6mim]Br. [C6mim ]Br induced oxidative stress of S. obliquus at the concentration of 1 mg/L and had environmental toxicity.
The effectsof ionic liquid 1-hexyl-3-methylimidazolium ([C6mim ]Br), with the concentrationsof 0, 1, 5, 10, 15 and 20 mg/L and exposed for the 24, 48, 72 and 96h respectively, on glutathione (GSH) and the enzymes in glutathione metabolism of Scenedesmus obliquus such as glutathione peroxidase (GPX), glutathione S-transferases (GST) and glutathione reductase (GR) were studied in the present study1 The results indicated that the GSH contents decreased with the concentration of [C6mim ]Br increasing at the 24, 48 and 72h, but it did not change when [C6mim ]Br = 1mg/L. The GSH contentswere similar to or lower than that of the control level at the 96h. The activities of GPX and GST increased markedly before 72h except for the activity of GST at the highest concentration (20 mg/L), but they both decreased to the control level at the 96h1 The activities of GR increased at the concentration of 1 mg/L and then decreased with the concentration increasing at the 24h, increased to the control level at the 48h, and then reached its peak at the 72h (when [C6mim ]Br≥10 mg/L the GR activities exceeded the control level), but at the 96h, it decreased markedly even weaker than the control level. GR was the enzyme that limited the reaction velocity in the system of glutathione cycle and the GST was the most active and sensitive enzyme. It could be used as sensitive biomarkers under the stress induced by [C6mim]Br. [C6mim ]Br induced oxidative stress of S. obliquus at the concentration of 1 mg/L and had environmental toxicity.
Open Access
Abstract：
W ith many advantageous features such as small size, high production and fertilization in vitro, zebrafish has become a kind of themodel creature for the investigation of vertebrate development and human diseases. Sowe set up a transgenic zebrafish model to investigate the β-cell development1 Firstly, we obtained an INS: GFP construction that contains the zebrafish insulin (INS) promoter and green fluorescent protein (GFP).Secondly, we injected the construction into the cytoplasm of one-cell-stage embryos. F inally, we gained germline INS transgenic zebrafish that d isplayed highly specific β-cell expression ofGFP in both larvae and adult1 By following GFP expression, pancreas formation was detected at the 18h post-fertilization in the earliest time points between the second bilateral som ites, a group of GFP-positive cells located from ventral to the notochord. From day 1 to 5 post-fertilization,the number of insu lin/GFP expressing cells migrated and formed a right organ. Thus, ourworks demonstrated that the transgenic line provided a conven ient and d irect expermi ental tool in analyzing endocrine pancreas development, injury and recovery.
W ith many advantageous features such as small size, high production and fertilization in vitro, zebrafish has become a kind of themodel creature for the investigation of vertebrate development and human diseases. Sowe set up a transgenic zebrafish model to investigate the β-cell development1 Firstly, we obtained an INS: GFP construction that contains the zebrafish insulin (INS) promoter and green fluorescent protein (GFP).Secondly, we injected the construction into the cytoplasm of one-cell-stage embryos. F inally, we gained germline INS transgenic zebrafish that d isplayed highly specific β-cell expression ofGFP in both larvae and adult1 By following GFP expression, pancreas formation was detected at the 18h post-fertilization in the earliest time points between the second bilateral som ites, a group of GFP-positive cells located from ventral to the notochord. From day 1 to 5 post-fertilization,the number of insu lin/GFP expressing cells migrated and formed a right organ. Thus, ourworks demonstrated that the transgenic line provided a conven ient and d irect expermi ental tool in analyzing endocrine pancreas development, injury and recovery.
Open Access
Abstract：
Grass carp (Ctenopharyngodon idellus) is one of the most important freshwater species in aquaculture. Meanwhile, the grass carp is originally distributes in China, and then it has been introduced into more than 100 countries for aquatic weed control and aquaculture since 1960s. In the past five decades, the grass carps have been adapted to the local environment and developed local groups. However, the genetic variation among the grass carps in native and introduced regions, aswell the genetic phylogeny, is not clear1Meanwhile, there is no available literature to clarifywhich river systems in China are the most likely origins of colonized populations in introduced regions1 In this study, partial sequences of the mitochondrial D-Loop (764bp), CO II + tRNA (719bp) were analyzed from native (the Yangtze, Amur and Pear.Rivers in China) and introduced (the Danube River in Hungary, theMississippi River in USA and the Tonegawa River in Japan) populations of the grass carp. The data of the two mtDNA fragments showed no competitive with the ILD (Incongruence Length Difference) test (p =0.42), and they could combine together as one data. The results indicated that there were the total of 32 haplotypes in all specimens, and 5 haplotypes were shared, all other haplotypes were singletons. In the 5 shared haplotypes, one was found in all populations, one in Amur River and Pearl River, two in China and Hungary, and the last one was found only in China. The genetic variation in the native populationswas higher than that in the colonized populations. In the native populations, the genetic diversity ordered as the Pearl Rivers (π=0.0042) > Yangtze River (π =0.0028)>Amur River (π = 0.0013). In the introduced populations, the genetic diversity ordered as the Danube River (π =0.0019) > Mississippi River (π =0.0010) > Tonegawa River (π =0.0001). The analysis of AMOVA using Arlequin 3.01 indicated that the variation mostly existed within populations (77.27%), but it was very low contribution from the sampling regions (0.38%). The pairwise FSTvalues demonstrated that there was a significant differentiation in most pairwise populations. The Tajima’s D values were significant negative in the populations of the Amur River andMississippi River (was marginable significance in Tonegawa River), which demonstrating the recent population expansion in their histories, and were positive in the other populations. Base on the software TCS 1.21, the haplotype network showed that the Yangtze River population would be the most original and then expanded to other rivers. Based on the base composition, transition/transversion values from the softwareMEGA4, the gene flow among populations using the software Migrate-2.4.3 showed that the Danube River population and the Tonegawa River population might have two origins from China, namely the Yangtze and Amur River, the Mississippi River population might have three origins, the Yangtze, Amur and Pearl Rivers. The gene flow gave a sign that all grass carp populations would be derived from the Yangtze River, which is agreement with the results of the haplotype network.
Grass carp (Ctenopharyngodon idellus) is one of the most important freshwater species in aquaculture. Meanwhile, the grass carp is originally distributes in China, and then it has been introduced into more than 100 countries for aquatic weed control and aquaculture since 1960s. In the past five decades, the grass carps have been adapted to the local environment and developed local groups. However, the genetic variation among the grass carps in native and introduced regions, aswell the genetic phylogeny, is not clear1Meanwhile, there is no available literature to clarifywhich river systems in China are the most likely origins of colonized populations in introduced regions1 In this study, partial sequences of the mitochondrial D-Loop (764bp), CO II + tRNA (719bp) were analyzed from native (the Yangtze, Amur and Pear.Rivers in China) and introduced (the Danube River in Hungary, theMississippi River in USA and the Tonegawa River in Japan) populations of the grass carp. The data of the two mtDNA fragments showed no competitive with the ILD (Incongruence Length Difference) test (p =0.42), and they could combine together as one data. The results indicated that there were the total of 32 haplotypes in all specimens, and 5 haplotypes were shared, all other haplotypes were singletons. In the 5 shared haplotypes, one was found in all populations, one in Amur River and Pearl River, two in China and Hungary, and the last one was found only in China. The genetic variation in the native populationswas higher than that in the colonized populations. In the native populations, the genetic diversity ordered as the Pearl Rivers (π=0.0042) > Yangtze River (π =0.0028)>Amur River (π = 0.0013). In the introduced populations, the genetic diversity ordered as the Danube River (π =0.0019) > Mississippi River (π =0.0010) > Tonegawa River (π =0.0001). The analysis of AMOVA using Arlequin 3.01 indicated that the variation mostly existed within populations (77.27%), but it was very low contribution from the sampling regions (0.38%). The pairwise FSTvalues demonstrated that there was a significant differentiation in most pairwise populations. The Tajima’s D values were significant negative in the populations of the Amur River andMississippi River (was marginable significance in Tonegawa River), which demonstrating the recent population expansion in their histories, and were positive in the other populations. Base on the software TCS 1.21, the haplotype network showed that the Yangtze River population would be the most original and then expanded to other rivers. Based on the base composition, transition/transversion values from the softwareMEGA4, the gene flow among populations using the software Migrate-2.4.3 showed that the Danube River population and the Tonegawa River population might have two origins from China, namely the Yangtze and Amur River, the Mississippi River population might have three origins, the Yangtze, Amur and Pearl Rivers. The gene flow gave a sign that all grass carp populations would be derived from the Yangtze River, which is agreement with the results of the haplotype network.
Open Access
Abstract：
An experiment was conducted to study the effects of copper (Cu2+) on the antioxidant enzymes activities of the Bellamya purificat, such as superoxide dismatase (SOD), catalase (CAT), glutathione S-transferase (GST), concentrations of glutathione (GSH) and metallothionein (MT) at different concentrations of Cu2+(0, 0.005, 0.01, 0.02 and 0.05 mg/L) and different exposure times (0-14d). In order to evaluate the mechanisms of oxidative stress and damnification of Cu2+ on B. purificat, gills and livers were chosen to analyse the biochemical responses, because these organs were brought into contactwith environmental pollutants nearly. The results showed that Cu2+ had significant influence on the activities of SOD, CAT, GST and the concentrations of GSH, MT in both gills and livers of B. purificat, and such effects are significantly related to increased exposure time and dosage. The antioxidant enzymes activities in gills and livers could be markedly activated at the beginning days of Cu2+ exposure, such as SOD in 4d, CAT in 3d, and GST in 4d after exposure. The activities of SOD, CAT and GST decreased with the increase of exposure time, till theywere inclined to be inhibited in the 5d. On the last day of exposure, the antioxidant enzymes activities in treatmentswith 0.005mg/L of Cu2+ approached to the normal value, in 0.05 mg/L of Cu2+ were inhibited, and in 0.01mg/L of Cu2+ were induced. The activities of enzymes in treatments with 0.02 mg/L of Cu2+ was activated in liver and reversed in gill. Changes of GSH in livers and gills consisted with that of GST, which was enhanced when Cu2+ exposure began in several days. GSH concentrations in liverswere induced after 5-day-Cu2+ exposure, which in gills were induced after 4-day-Cu2+ exposure. GSH contents increased in low dosage (0.005 mg/L) group and decreased in high dosage (0.05 mg/L) group along with continuous Cu2+ exposure. TheMTs (concentration of metallothionein) in livers and gills of B. purificat were induced during the whole exposure process. MTs in all groups increased significantly within 12h Cu2+ exposure (p 2+ was extremely significantly induced during the whole process (p 2+. These results suggested that all these parameters above were sensitive to the exposure of Cu2+ and could be used as biomarkers to evaluate the aquatic environment Cu2+ pollution and its ecological risk.
An experiment was conducted to study the effects of copper (Cu2+) on the antioxidant enzymes activities of the Bellamya purificat, such as superoxide dismatase (SOD), catalase (CAT), glutathione S-transferase (GST), concentrations of glutathione (GSH) and metallothionein (MT) at different concentrations of Cu2+(0, 0.005, 0.01, 0.02 and 0.05 mg/L) and different exposure times (0-14d). In order to evaluate the mechanisms of oxidative stress and damnification of Cu2+ on B. purificat, gills and livers were chosen to analyse the biochemical responses, because these organs were brought into contactwith environmental pollutants nearly. The results showed that Cu2+ had significant influence on the activities of SOD, CAT, GST and the concentrations of GSH, MT in both gills and livers of B. purificat, and such effects are significantly related to increased exposure time and dosage. The antioxidant enzymes activities in gills and livers could be markedly activated at the beginning days of Cu2+ exposure, such as SOD in 4d, CAT in 3d, and GST in 4d after exposure. The activities of SOD, CAT and GST decreased with the increase of exposure time, till theywere inclined to be inhibited in the 5d. On the last day of exposure, the antioxidant enzymes activities in treatmentswith 0.005mg/L of Cu2+ approached to the normal value, in 0.05 mg/L of Cu2+ were inhibited, and in 0.01mg/L of Cu2+ were induced. The activities of enzymes in treatments with 0.02 mg/L of Cu2+ was activated in liver and reversed in gill. Changes of GSH in livers and gills consisted with that of GST, which was enhanced when Cu2+ exposure began in several days. GSH concentrations in liverswere induced after 5-day-Cu2+ exposure, which in gills were induced after 4-day-Cu2+ exposure. GSH contents increased in low dosage (0.005 mg/L) group and decreased in high dosage (0.05 mg/L) group along with continuous Cu2+ exposure. TheMTs (concentration of metallothionein) in livers and gills of B. purificat were induced during the whole exposure process. MTs in all groups increased significantly within 12h Cu2+ exposure (p 2+ was extremely significantly induced during the whole process (p 2+. These results suggested that all these parameters above were sensitive to the exposure of Cu2+ and could be used as biomarkers to evaluate the aquatic environment Cu2+ pollution and its ecological risk.
Open Access
Abstract：
neutral protease productwith an activity of 8000 u/g was used in the experiment. A basal diet without exogenous enzyme inclusion and four test diets adding 0.5‰, 1‰, 2‰ and 3‰ of the enzyme product respectivelywere prepared to feed five triplicate groups of fish with an initial average body weight of (3.03 ±0.04) g. The feeding trial was conducted in 15 re circulating tank systems (80L each) at a controlled water temperature of 25 ±0.5 ℃ and lasted for eight weeks. At the end of eightweeks, the weight gain of fish fed a diet with 0.5‰ of enzyme product showed no significant difference with that of fish fed basal diet (p >0.05). When fish fed a diet with 1‰ of enzyme product, the weight gain increased significantly (p 0.05). However, the apparent digestibility of dietary protein of fish fed four test dietswere significantly higher than that of fish fed the basal diet (p <0.05). The hepato-pancreas protease activity increased with increasing dietary supplementing the enzyme product up to 1‰, but above this level, it appeared to keep stable. In conclusion, under the condition of this experiment, adding 1‰ -3‰ neutral protease product to fingerling black carp diet could promote feed ingest and digest capacity of dietary protein, and as a result, improve fish growthand feed conversion.
neutral protease productwith an activity of 8000 u/g was used in the experiment. A basal diet without exogenous enzyme inclusion and four test diets adding 0.5‰, 1‰, 2‰ and 3‰ of the enzyme product respectivelywere prepared to feed five triplicate groups of fish with an initial average body weight of (3.03 ±0.04) g. The feeding trial was conducted in 15 re circulating tank systems (80L each) at a controlled water temperature of 25 ±0.5 ℃ and lasted for eight weeks. At the end of eightweeks, the weight gain of fish fed a diet with 0.5‰ of enzyme product showed no significant difference with that of fish fed basal diet (p >0.05). When fish fed a diet with 1‰ of enzyme product, the weight gain increased significantly (p 0.05). However, the apparent digestibility of dietary protein of fish fed four test dietswere significantly higher than that of fish fed the basal diet (p <0.05). The hepato-pancreas protease activity increased with increasing dietary supplementing the enzyme product up to 1‰, but above this level, it appeared to keep stable. In conclusion, under the condition of this experiment, adding 1‰ -3‰ neutral protease product to fingerling black carp diet could promote feed ingest and digest capacity of dietary protein, and as a result, improve fish growthand feed conversion.
Open Access
Abstract：
In higher plant, Δ9 desaturase introduces the first double bond into saturated fatty acids, resulting inthe corresponding monounsaturated fatty acids.We have cloned gene, designated as PvfadA, for C18∶0Δ9 desaturase catalytic activity from Pavlova viridis by RT-PCR, RNA ligase mediated RACE (RLM-RACE) and Overlap-PCR strategy. This desaturase, when expressed in Escherichia coli, desaturated stearic acid to yield oleic acid, but did not desaturate other fatty acids in E. coli. These results indicate that PvFadA is specific to stearic acid. The deduced amino acid sequences of PvFadA show that a putative (D /E) X2HX～100(D /E) X2 H metal binding motif, which specifically existed in acyl-ACP desaturase. Moreover, Amino acids of PvFadA are similar in part to those of acyl-ACP desaturases from higher plant, such as A rabidopsis thaliana, Oryza sativa and Glycine max, but not to those of acyl-lipid desaturases of Cyanobacteria, and acyl-CoA desaturases of higher plant. In addition, the 3D2model structure of PvFadA is composed of 11 helixes, moreover, α3, α4, α6 andα7 form a core 42helix bundle to regards as an active center in this enzyme, similar as acyl-ACP desaturase of Ricinus communis and M ycobacterium tuberculosis H37Rv.
In higher plant, Δ9 desaturase introduces the first double bond into saturated fatty acids, resulting inthe corresponding monounsaturated fatty acids.We have cloned gene, designated as PvfadA, for C18∶0Δ9 desaturase catalytic activity from Pavlova viridis by RT-PCR, RNA ligase mediated RACE (RLM-RACE) and Overlap-PCR strategy. This desaturase, when expressed in Escherichia coli, desaturated stearic acid to yield oleic acid, but did not desaturate other fatty acids in E. coli. These results indicate that PvFadA is specific to stearic acid. The deduced amino acid sequences of PvFadA show that a putative (D /E) X2HX～100(D /E) X2 H metal binding motif, which specifically existed in acyl-ACP desaturase. Moreover, Amino acids of PvFadA are similar in part to those of acyl-ACP desaturases from higher plant, such as A rabidopsis thaliana, Oryza sativa and Glycine max, but not to those of acyl-lipid desaturases of Cyanobacteria, and acyl-CoA desaturases of higher plant. In addition, the 3D2model structure of PvFadA is composed of 11 helixes, moreover, α3, α4, α6 andα7 form a core 42helix bundle to regards as an active center in this enzyme, similar as acyl-ACP desaturase of Ricinus communis and M ycobacterium tuberculosis H37Rv.
Open Access
Abstract：
A 162weeks growth was conducted to evaluate the effect of replacement of dietary fishmeal by soybean meal on growth performance, feed utilization, nitrogen metabolism and immunity in gibel carp. Four isonitrogenous and isocaloric dietswere formulated. Each dietwas fed to triplicate groups of fish with the initial weight at about 2.32 g. Soybean meal was used to replace 0 (Control, D1), 20% (D2), 80% (D3) and 100% (D4) of dietary fishmeal protein1 The fish was reared in a semi-recirculating system. During the experiment, water temperature was 23-30℃, photoperiod was 12D∶12L with the light period from 08: 00 to 20: 00, dissolved oxygen was above 5 mg/L, ammonia2N (NH4+-N plus NH3-N) was less than 0.5 mg/L, pH was about 6.4. Fish were fed to satiation twice daily (9: 00 and 15: 00). At the beginning of the experiment, healthy fish (initial body weight about 2.32 g) were batch weighed after 24h feed deprivation and randomly distributed into the 12 tanks (40 fish per tank). The tankswere randomly assigned the four diets. Fifty fish were taken from the remaining fish and frozen for initial fish body chemical analysis. During the experiment, an excess amount of feed was fed to fish and uneaten feed were collected after 1h in each feeding, dried at 60℃ and reweighed. Leaching rate of uneaten feed in tankswas estimated by placingweighed feeds into a tank without fish for 1h and then recovering, drying and reweighing. The average leaching rate was used to calibrate the amount of uneaten feed1 Faeceswere collected after uneaten feed collection at the startof the experiment and through all the experimentperiod after7d. To minimize nutrient leaching in faeces, only fresh and intact faeces were collected1 Faeces were dried at 70℃ for digestibility determination.At the end of the trial, the fish were starved for 1d and batch weighed1 Fish were killed by a blow on the head and blood sampleswere collected (24h after last feeding) from the caudal vein of six fish from each tank at the end of the feeding trial by using heparinized syringes. Blood was centrifuged at 3500 r/min for 15 min, plasma-separated and stored at -80 ℃. The remaining fish in each tank were taken for final fish body composition analysis1 The results showed that feeding rate (FR), specific growth rate (SGR), feed conversion efficiency (FCE), protein retention efficiency (PRE) and energy retention efficiency (ERE) decreased significantly (p p p p p p <0.05). In conclusion, the results from this study showed adverse effects of inclusion of the soybean meal in dietson growth performance, feed utilization, nitrogen metabolism and immunity in gibel carp. The palatability was not negatively affected when soybean mealwas included in the diets1 Unbalanced amino acid composition of soybean meal diets seem to be the main reason to influence growth performance and nitrogen load of gibel carp.
A 162weeks growth was conducted to evaluate the effect of replacement of dietary fishmeal by soybean meal on growth performance, feed utilization, nitrogen metabolism and immunity in gibel carp. Four isonitrogenous and isocaloric dietswere formulated. Each dietwas fed to triplicate groups of fish with the initial weight at about 2.32 g. Soybean meal was used to replace 0 (Control, D1), 20% (D2), 80% (D3) and 100% (D4) of dietary fishmeal protein1 The fish was reared in a semi-recirculating system. During the experiment, water temperature was 23-30℃, photoperiod was 12D∶12L with the light period from 08: 00 to 20: 00, dissolved oxygen was above 5 mg/L, ammonia2N (NH4+-N plus NH3-N) was less than 0.5 mg/L, pH was about 6.4. Fish were fed to satiation twice daily (9: 00 and 15: 00). At the beginning of the experiment, healthy fish (initial body weight about 2.32 g) were batch weighed after 24h feed deprivation and randomly distributed into the 12 tanks (40 fish per tank). The tankswere randomly assigned the four diets. Fifty fish were taken from the remaining fish and frozen for initial fish body chemical analysis. During the experiment, an excess amount of feed was fed to fish and uneaten feed were collected after 1h in each feeding, dried at 60℃ and reweighed. Leaching rate of uneaten feed in tankswas estimated by placingweighed feeds into a tank without fish for 1h and then recovering, drying and reweighing. The average leaching rate was used to calibrate the amount of uneaten feed1 Faeceswere collected after uneaten feed collection at the startof the experiment and through all the experimentperiod after7d. To minimize nutrient leaching in faeces, only fresh and intact faeces were collected1 Faeces were dried at 70℃ for digestibility determination.At the end of the trial, the fish were starved for 1d and batch weighed1 Fish were killed by a blow on the head and blood sampleswere collected (24h after last feeding) from the caudal vein of six fish from each tank at the end of the feeding trial by using heparinized syringes. Blood was centrifuged at 3500 r/min for 15 min, plasma-separated and stored at -80 ℃. The remaining fish in each tank were taken for final fish body composition analysis1 The results showed that feeding rate (FR), specific growth rate (SGR), feed conversion efficiency (FCE), protein retention efficiency (PRE) and energy retention efficiency (ERE) decreased significantly (p p p p p p <0.05). In conclusion, the results from this study showed adverse effects of inclusion of the soybean meal in dietson growth performance, feed utilization, nitrogen metabolism and immunity in gibel carp. The palatability was not negatively affected when soybean mealwas included in the diets1 Unbalanced amino acid composition of soybean meal diets seem to be the main reason to influence growth performance and nitrogen load of gibel carp.
Open Access
2009, 33(4): 749-755.
Abstract：
P450 aromatase (P450arom), an enzyme catalyzing the synthesis of estrogens, is thought to play a key role in sex differentiation of neural and reproductive development in vertebrates. Most of the mammals have only one aromatase, but many teleost fish, including the zebrafish (Danio rerio) and medaka (Oryzias latipes) have two isoforms of aromatase encoded by two distinct genes, Cyp19a expressed predominantly in the ovary and Cyp19b in the brain. Gobiocypris rarus is an emerging model fish in China because of its small size, transparent embryonic biology, spawning round the year, easy breeding, short generation and sensitivity in toxicology. However, the mechanisms of sex determination and differentiation are still unclear in this fish. Aromatase as the important factor in the differentiation of sex is also unavailable, so that the exact roles of aromatase gene in neural or ovarian development in this fish are unclear. To understand the mechanisms of sex differentiation and the role of aromatase in this process, we cloned the partial sequences of Cyp19b cDNA of Gobiocypris rarus by reverse transcription-polymerase chain reaction with degenerate primers dependant on the conservative sequences of the gene in other vertebrates, and we also examined its expression pattern in the tissues of adult fish and the developmental processof embryos in this fish by gene specific primers. The partial sequence of Cyp19b of Gobiocypris rarus we cloned consisted of 1070 base pairswhich encoded 357 amino acids1 Structural analysis of the deduced amino acid sequence indicated that it contained three specific domains of aromatases, substrate2binding loop, distal helix I and the steroid2binding domain1 Multiple alignment and phylogenetic analysis showed that this protein of Gobiocypris rarus shared 57% -93% identitieswith P450arom proteinsof other species and itwasmost similar to P450aromB s of Danio rerio, Carassius auratus and Cyprinus carpio in 91%, 92% and 93%, respectively. This result indicated that the gene we got was Cyp19b of Gobiocypris rarus. The tissue expression pattern analysis by RT-PCR with specific primers showed that Cyp19b was predominantly expressed in the brain in both sexes, and the expression in the brain of female was slightly higher in female but not obviously stronger than that in the male in statistics. Itwas also expressed in eye, gill, kidney, intestine of both sexes, but not detectable expressions in other tissue like heart, liver, spleen, air bladder, and muscle. Ontogenic analysis by RT2PCR with specific primers showed that no expression was detected in the zygote, and the onset of expression of Cyp19b was from blastula, then the expression reached a higher level in neurula, after that it declined. The expression of Cyp19b burst again in 5d after hatching and it kept in a very high level till 30d after hatching. These results indicate that Cyp19b is expressed predominantly in the brain of adult fish, and it is also expressed highly in the stage of neurula. Cyp19b may play important roles in the development of central neural system and the sexual differentiation of the brain1 The beginning of the expression from blastula suggest that Cyp19b is not a maternal factor for the embryos of Gobiocypris rarus.
P450 aromatase (P450arom), an enzyme catalyzing the synthesis of estrogens, is thought to play a key role in sex differentiation of neural and reproductive development in vertebrates. Most of the mammals have only one aromatase, but many teleost fish, including the zebrafish (Danio rerio) and medaka (Oryzias latipes) have two isoforms of aromatase encoded by two distinct genes, Cyp19a expressed predominantly in the ovary and Cyp19b in the brain. Gobiocypris rarus is an emerging model fish in China because of its small size, transparent embryonic biology, spawning round the year, easy breeding, short generation and sensitivity in toxicology. However, the mechanisms of sex determination and differentiation are still unclear in this fish. Aromatase as the important factor in the differentiation of sex is also unavailable, so that the exact roles of aromatase gene in neural or ovarian development in this fish are unclear. To understand the mechanisms of sex differentiation and the role of aromatase in this process, we cloned the partial sequences of Cyp19b cDNA of Gobiocypris rarus by reverse transcription-polymerase chain reaction with degenerate primers dependant on the conservative sequences of the gene in other vertebrates, and we also examined its expression pattern in the tissues of adult fish and the developmental processof embryos in this fish by gene specific primers. The partial sequence of Cyp19b of Gobiocypris rarus we cloned consisted of 1070 base pairswhich encoded 357 amino acids1 Structural analysis of the deduced amino acid sequence indicated that it contained three specific domains of aromatases, substrate2binding loop, distal helix I and the steroid2binding domain1 Multiple alignment and phylogenetic analysis showed that this protein of Gobiocypris rarus shared 57% -93% identitieswith P450arom proteinsof other species and itwasmost similar to P450aromB s of Danio rerio, Carassius auratus and Cyprinus carpio in 91%, 92% and 93%, respectively. This result indicated that the gene we got was Cyp19b of Gobiocypris rarus. The tissue expression pattern analysis by RT-PCR with specific primers showed that Cyp19b was predominantly expressed in the brain in both sexes, and the expression in the brain of female was slightly higher in female but not obviously stronger than that in the male in statistics. Itwas also expressed in eye, gill, kidney, intestine of both sexes, but not detectable expressions in other tissue like heart, liver, spleen, air bladder, and muscle. Ontogenic analysis by RT2PCR with specific primers showed that no expression was detected in the zygote, and the onset of expression of Cyp19b was from blastula, then the expression reached a higher level in neurula, after that it declined. The expression of Cyp19b burst again in 5d after hatching and it kept in a very high level till 30d after hatching. These results indicate that Cyp19b is expressed predominantly in the brain of adult fish, and it is also expressed highly in the stage of neurula. Cyp19b may play important roles in the development of central neural system and the sexual differentiation of the brain1 The beginning of the expression from blastula suggest that Cyp19b is not a maternal factor for the embryos of Gobiocypris rarus.
Open Access
2009, 33(4): 756-761.
Open Access
2009, 33(4): 762-766.
Open Access
Open Access
2009, 33(4): 772-777.
Open Access
Open Access
2009, 33(4): 782-788.
