2023 Vol. 47 No. 2
Open Access
Abstract：
The effects of methanotroph (Methylococcus capsulatus, Barh) bacteria meal (MBM, FeedKind®) replaces fishmeal (FM) on the growth performance and antioxidant capacity of Trachinotus ovatus (initial mean weight 34.88±1.13 g) were conducted through a 56-day breeding trial. MBM at 0, 3%, 7% and 10.5% were added to replace fishmeal at 0, 10%, 20% and 30%, to formulate four isonitrogenous and isolipidic feeds named MBM0, MBM10, MBM20 and MBM30, respectively. The results of the experiment showed that there was no significant difference in the final mean weight, weight gain rate, specific growth rate, survival rate, hepatosomatic index, visceral index and feed factor between the groups as the MBM content in the diets increased (P>0.05). The condition factor of the MBM30 group was significantly higher than that of the MBM0 group (P<0.05). The crude protein content of whole fish in each group was not significantly different (P>0.05), while the crude fat content of whole fish in the MBM20 group was significantly higher than that in the MBM0 and MBM10 groups (P<0.05). The crude fat content of dorsal muscle in the MBM20 and MBM30 groups was significantly higher than that in the MBM0 group (P<0.05), and there was a significant positive correlation between the crude fat content in dorsal muscle and the proportion of fishmeal replaced by MBM (P<0.05). Serum triglycerides were significantly lower in the MBM20 and MBM30 groups than those in MBM0 group (P<0.05), serum glutathione transaminase activity was significantly higher in the MBM20 group than that in the MBM0 group (P<0.05), and serum albumin was significantly higher in the MBM10 group than those in MBM0 group (P<0.05). Total serum antioxidant capacity in MBM20 group was not significantly different with the MBM0 group (P> 0.05), while significantly higher than that in the MBM10 and MBM30 groups (P<0.05). Intestinal superoxide dismutase activity in the MBM20 group was significantly higher than that in the rest of the groups (P<0.05). Vacuolar area in liver through H&E-stained was significantly higher in the MBM20 and MBM30 groups than that in the MBM0 group (P<0.05). In conclusion, at 35% fishmeal content in the basal diet, MBM could replace 20%—30% of fishmeal without negatively affecting growth performance, morphological indices, body composition and serum biochemical indices of Trachinotus ovatus.
The effects of methanotroph (Methylococcus capsulatus, Barh) bacteria meal (MBM, FeedKind®) replaces fishmeal (FM) on the growth performance and antioxidant capacity of Trachinotus ovatus (initial mean weight 34.88±1.13 g) were conducted through a 56-day breeding trial. MBM at 0, 3%, 7% and 10.5% were added to replace fishmeal at 0, 10%, 20% and 30%, to formulate four isonitrogenous and isolipidic feeds named MBM0, MBM10, MBM20 and MBM30, respectively. The results of the experiment showed that there was no significant difference in the final mean weight, weight gain rate, specific growth rate, survival rate, hepatosomatic index, visceral index and feed factor between the groups as the MBM content in the diets increased (P>0.05). The condition factor of the MBM30 group was significantly higher than that of the MBM0 group (P<0.05). The crude protein content of whole fish in each group was not significantly different (P>0.05), while the crude fat content of whole fish in the MBM20 group was significantly higher than that in the MBM0 and MBM10 groups (P<0.05). The crude fat content of dorsal muscle in the MBM20 and MBM30 groups was significantly higher than that in the MBM0 group (P<0.05), and there was a significant positive correlation between the crude fat content in dorsal muscle and the proportion of fishmeal replaced by MBM (P<0.05). Serum triglycerides were significantly lower in the MBM20 and MBM30 groups than those in MBM0 group (P<0.05), serum glutathione transaminase activity was significantly higher in the MBM20 group than that in the MBM0 group (P<0.05), and serum albumin was significantly higher in the MBM10 group than those in MBM0 group (P<0.05). Total serum antioxidant capacity in MBM20 group was not significantly different with the MBM0 group (P> 0.05), while significantly higher than that in the MBM10 and MBM30 groups (P<0.05). Intestinal superoxide dismutase activity in the MBM20 group was significantly higher than that in the rest of the groups (P<0.05). Vacuolar area in liver through H&E-stained was significantly higher in the MBM20 and MBM30 groups than that in the MBM0 group (P<0.05). In conclusion, at 35% fishmeal content in the basal diet, MBM could replace 20%—30% of fishmeal without negatively affecting growth performance, morphological indices, body composition and serum biochemical indices of Trachinotus ovatus.
Open Access
2023, 47(2): 204-216.
DOI: 10.7541/2023.2022.0376
Abstract：
To evaluate the effects of dietary coenzyme Q10 (CoQ10) on growth performance, body composition, antioxidant capacity, tissue structure and gene expression in juvenile genetically improved farmed tilapia (GIFT), juvenile GIFT tilapia with initial body weight of (19.97±0.13) g were fed with four diets containing 0, 40, 80 and 120 mg/kg CoQ10 for a 56-day trial. The results showed that the final body weight (FBW), feeding rate (FR), specific growth rate (SGR) and feed efficiency (FE) of supplemented CoQ10 groups had no significant difference compared with the control group, while 120 mg/kg CoQ10 group had the highest final body weight, specific growth rate and feed efficiency. The dry matter digestibility (DMD) of juvenile GIFT tilapia significantly increased when CoQ10 content was 120 mg/kg. The serum activities of catalase (CAT) and glutathione peroxidase (GSH-Px) in CoQ10 groups were significantly higher than those in the control group. The CAT and GSH-Px activities in liver of the CoQ10 groups were significantly higher than those in the control group. The SOD and GST activities in liver of 80 and 120 mg/kg CoQ10 groups were significantly higher than those in control group while malondialdehyde (MDA) content was significantly decreased. There was no significant difference in the moisture, crude protein and ash contents in the eviscerated whole fish among all groups. Compared with the control group, 120 mg/kg CoQ10 significantly decreased crude lipid content in the eviscerated whole fish. There was no significant difference in the moisture, crude protein, crude lipid and ash contents in the visceral mass among all groups. No significant histological changes in liver were identified in all groups. The intestinal villi length, villi density and muscle thickness in the 120 mg/kg group significantly increased. The expression of sod, cat, gsh-px, gst and igm mRNA in 120 mg/kg CoQ10 group were significantly higher than the control group, while the expression of il-1β and il-8 mRNA significantly decreased in the CoQ10 groups compared with the control group. In the challenge experiment by intraperitoneal injection with Aeromonas hydrophila, the cumulative survival rate of juvenile GIFT tilapia in 80 and 120 mg/kg CoQ10 groups was significantly higher than that in control group. In conclusion, these results suggested that dietary CoQ10 content within 120 mg/kg has no adverse effects on juvenile GIFT tilapia, dietary 120 mg/kg CoQ10 could improve digestibility, antioxidant abilities, liver antioxidant-related gene expression and resistance to Aeromonas hydrophila of juvenile GIFT tilapia.
To evaluate the effects of dietary coenzyme Q10 (CoQ10) on growth performance, body composition, antioxidant capacity, tissue structure and gene expression in juvenile genetically improved farmed tilapia (GIFT), juvenile GIFT tilapia with initial body weight of (19.97±0.13) g were fed with four diets containing 0, 40, 80 and 120 mg/kg CoQ10 for a 56-day trial. The results showed that the final body weight (FBW), feeding rate (FR), specific growth rate (SGR) and feed efficiency (FE) of supplemented CoQ10 groups had no significant difference compared with the control group, while 120 mg/kg CoQ10 group had the highest final body weight, specific growth rate and feed efficiency. The dry matter digestibility (DMD) of juvenile GIFT tilapia significantly increased when CoQ10 content was 120 mg/kg. The serum activities of catalase (CAT) and glutathione peroxidase (GSH-Px) in CoQ10 groups were significantly higher than those in the control group. The CAT and GSH-Px activities in liver of the CoQ10 groups were significantly higher than those in the control group. The SOD and GST activities in liver of 80 and 120 mg/kg CoQ10 groups were significantly higher than those in control group while malondialdehyde (MDA) content was significantly decreased. There was no significant difference in the moisture, crude protein and ash contents in the eviscerated whole fish among all groups. Compared with the control group, 120 mg/kg CoQ10 significantly decreased crude lipid content in the eviscerated whole fish. There was no significant difference in the moisture, crude protein, crude lipid and ash contents in the visceral mass among all groups. No significant histological changes in liver were identified in all groups. The intestinal villi length, villi density and muscle thickness in the 120 mg/kg group significantly increased. The expression of sod, cat, gsh-px, gst and igm mRNA in 120 mg/kg CoQ10 group were significantly higher than the control group, while the expression of il-1β and il-8 mRNA significantly decreased in the CoQ10 groups compared with the control group. In the challenge experiment by intraperitoneal injection with Aeromonas hydrophila, the cumulative survival rate of juvenile GIFT tilapia in 80 and 120 mg/kg CoQ10 groups was significantly higher than that in control group. In conclusion, these results suggested that dietary CoQ10 content within 120 mg/kg has no adverse effects on juvenile GIFT tilapia, dietary 120 mg/kg CoQ10 could improve digestibility, antioxidant abilities, liver antioxidant-related gene expression and resistance to Aeromonas hydrophila of juvenile GIFT tilapia.
Open Access
Abstract：
The experiment was conducted to investigate the effects of dietary protein source and stocking density on growth performance, body composition and serum biochemical parameters of grass carp (Ctenopharyngodon idellus). A two-factor orthogonal experiment (3×5) was used to evaluate the effects of soybean meal (SM), Clostridium autoethanogenum protein (CAP), Tenebrio molito (TM), cottonseed protein concentrate (CPC) and Chlorella (CH) for grass carps with three stocking density. Five isonitrogenous and isoenergetic diets were prepared with the five protein sources as a single protein source, respectively. Grass carps with an initial body weight of (5.36±0.18) g were fed with the five test diets at three stocking density (0.11, 0.16 and 0.21 kg/m3,) for 60 days in pond cages (1.0 m×1.0 m×1.5 m), respectively. The results showed that the feed coefficient (FCR) increased, and the specific growth rate (SGR), weight gain rate (WGR), protein efficiency (PER) and liver index (HSI) decreased with the increase of stocking density. Under the three stocking densities, FCR in TM group was significantly higher than that of other protein source groups (P<0.05), and FBW, SGR, WGR and PER were significantly lower than those in other protein source groups (P<0.05). The growth performance of grass carp in the 0.11 and 0.16 kg/m3 stocking density groups were similar, and were significantly better than that in the 0.21 kg/m3 stocking density group (P<0.05). Protein source and stocking density had no significant effects on the moisture, crude protein and ash content of the whole grass carp (P>0.05). The crude fat content of grass carp in the 0.21 kg/m3 stocking density group was significantly lower than that in other stocking density groups (P<0.05), and the serum biochemical indexes of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and glucose (GLU) were significantly higher than those in other stocking density groups (P<0.05). Regardless of the stocking density, the serum albumin (ALB) content of the CH group was significantly higher than that in the CAP group, the TM group and the CPC group (P<0.05). The alkaline phosphatase activity of TM group was significantly higher than that in the CAP group (P<0.05). Based on the protein efficiency and weight gain rate, the ability of grass carp to utilize the five protein sources was CAP=CH=CPC =SM>TM.
The experiment was conducted to investigate the effects of dietary protein source and stocking density on growth performance, body composition and serum biochemical parameters of grass carp (Ctenopharyngodon idellus). A two-factor orthogonal experiment (3×5) was used to evaluate the effects of soybean meal (SM), Clostridium autoethanogenum protein (CAP), Tenebrio molito (TM), cottonseed protein concentrate (CPC) and Chlorella (CH) for grass carps with three stocking density. Five isonitrogenous and isoenergetic diets were prepared with the five protein sources as a single protein source, respectively. Grass carps with an initial body weight of (5.36±0.18) g were fed with the five test diets at three stocking density (0.11, 0.16 and 0.21 kg/m3,) for 60 days in pond cages (1.0 m×1.0 m×1.5 m), respectively. The results showed that the feed coefficient (FCR) increased, and the specific growth rate (SGR), weight gain rate (WGR), protein efficiency (PER) and liver index (HSI) decreased with the increase of stocking density. Under the three stocking densities, FCR in TM group was significantly higher than that of other protein source groups (P<0.05), and FBW, SGR, WGR and PER were significantly lower than those in other protein source groups (P<0.05). The growth performance of grass carp in the 0.11 and 0.16 kg/m3 stocking density groups were similar, and were significantly better than that in the 0.21 kg/m3 stocking density group (P<0.05). Protein source and stocking density had no significant effects on the moisture, crude protein and ash content of the whole grass carp (P>0.05). The crude fat content of grass carp in the 0.21 kg/m3 stocking density group was significantly lower than that in other stocking density groups (P<0.05), and the serum biochemical indexes of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and glucose (GLU) were significantly higher than those in other stocking density groups (P<0.05). Regardless of the stocking density, the serum albumin (ALB) content of the CH group was significantly higher than that in the CAP group, the TM group and the CPC group (P<0.05). The alkaline phosphatase activity of TM group was significantly higher than that in the CAP group (P<0.05). Based on the protein efficiency and weight gain rate, the ability of grass carp to utilize the five protein sources was CAP=CH=CPC =SM>TM.
Open Access
Abstract：
This article aims to study the effect of rapeseed meal and cottonseed meal on the muscle quality and the expression of genes related to muscle fiber development after replacing part of the fish meal in the diets of yellow catfish (Pelteobagrus fulvidraco). Five groups of equal nitrogen and equal energy diets were designed in the experiment. The group containing 25% fish meal was used as the control diet (FM), and rapeseed meal and cotton meal were mixed 3﹕2 to replace 10%, 20%, 30% and 40% fish meal, and then set up four test groups as RM10, RM20, RM30 and RM40, respectively. The juvenile yellow catfish with an initial body weight of (2.38±0.02) g were fed with the above five diets for 8 weeks. The experiment showed that, compared with the fishmeal group, as the replacement level exceeded 10%, the crude protein and crude fat in the muscle of yellow catfish decreased significantly when the replacement level increased, but there was no significant difference in moisture and ash. In addition, the content of hydroxyproline in muscle also showed a downward trend. Among the muscle fibers of yellow catfish, the number with a diameter of ≥50 μm decreased when the replacement level reached 10%, while the number of fibers with a diameter of ≤20 μm showed an upward trend. At the same time, the replacement of plant protein sources will also have a certain impact on the muscle texture of yellow catfish. In addition, the mRNA levels of muscle fiber development-related genes myod, myog, and mrf4 gradually increased as the replacement level reached 10%, while the gene expression of myf5 and mstn did not show significance between the groups. The expression of TOR and S6K1 decreased as the replacement level increased, and the expression of 4E-BP1 increased as the replacement level increased. Therefore, this study show that use of the rapeseed meal and cottonseed meal to replace more than 10% of the fish meal in the diet of yellow catfish juveniles will damage the muscle growth and muscle quality.
This article aims to study the effect of rapeseed meal and cottonseed meal on the muscle quality and the expression of genes related to muscle fiber development after replacing part of the fish meal in the diets of yellow catfish (Pelteobagrus fulvidraco). Five groups of equal nitrogen and equal energy diets were designed in the experiment. The group containing 25% fish meal was used as the control diet (FM), and rapeseed meal and cotton meal were mixed 3﹕2 to replace 10%, 20%, 30% and 40% fish meal, and then set up four test groups as RM10, RM20, RM30 and RM40, respectively. The juvenile yellow catfish with an initial body weight of (2.38±0.02) g were fed with the above five diets for 8 weeks. The experiment showed that, compared with the fishmeal group, as the replacement level exceeded 10%, the crude protein and crude fat in the muscle of yellow catfish decreased significantly when the replacement level increased, but there was no significant difference in moisture and ash. In addition, the content of hydroxyproline in muscle also showed a downward trend. Among the muscle fibers of yellow catfish, the number with a diameter of ≥50 μm decreased when the replacement level reached 10%, while the number of fibers with a diameter of ≤20 μm showed an upward trend. At the same time, the replacement of plant protein sources will also have a certain impact on the muscle texture of yellow catfish. In addition, the mRNA levels of muscle fiber development-related genes myod, myog, and mrf4 gradually increased as the replacement level reached 10%, while the gene expression of myf5 and mstn did not show significance between the groups. The expression of TOR and S6K1 decreased as the replacement level increased, and the expression of 4E-BP1 increased as the replacement level increased. Therefore, this study show that use of the rapeseed meal and cottonseed meal to replace more than 10% of the fish meal in the diet of yellow catfish juveniles will damage the muscle growth and muscle quality.
Open Access
Abstract：
The purpose of this study was to investigate the effects of cottonseed protein concentrate (CPC) instead of soybean meal on the growth performance, health status and flesh quality of grass carp (Ctenopharyngodon idella). Six isonitrogenous (crude protein: 29%) and isolipidic (crude lipid: 5%) diets were designed. CPC was used to replace 0 (C0), 15% (C15), 30% (C30), 45% (C45), 75% (C75) and 100% (C100) soybean meal in grass carp diets. The grass carp [initial weight of (502.46±0.40) g] were fed in pond cages for 90 days. The results showed that: (1) In terms of growth performance, there was no significant difference in specific growth rate (SGR) and feed conversion ratio (FCR) among groups (P>0.05). The viscerosomatic index (VSI) of grass carp in C45 group was significantly higher than that in C0 group (P<0.05). (2) In terms of health status, the albumin and globulin ratio (A/G) of serum in C100 group was significantly lower than that in C0 group (P<0.05), and the activity of serum superoxide dismutase (SOD) in C15 group was significantly higher than that in C0 group (P<0.05); There were no pathological changes in liver and muscle tissue of grass carp in each group. (3) In terms of flesh quality, compared with C0 group, the crude protein content of grass carp muscle in C75 group and the isoleucine content of C30 group increased significantly (P<0.05), the muscle springiness and adhesiveness of grass carp in C30, C45 and C100 groups increased significantly (P<0.05), and the sarcomere length of grass carp muscle in C75 and C100 groups increased significantly (P<0.05). The results showed that CPC can completely replace soybean meal in grass carp diets, improve its immunity and flesh quality.
The purpose of this study was to investigate the effects of cottonseed protein concentrate (CPC) instead of soybean meal on the growth performance, health status and flesh quality of grass carp (Ctenopharyngodon idella). Six isonitrogenous (crude protein: 29%) and isolipidic (crude lipid: 5%) diets were designed. CPC was used to replace 0 (C0), 15% (C15), 30% (C30), 45% (C45), 75% (C75) and 100% (C100) soybean meal in grass carp diets. The grass carp [initial weight of (502.46±0.40) g] were fed in pond cages for 90 days. The results showed that: (1) In terms of growth performance, there was no significant difference in specific growth rate (SGR) and feed conversion ratio (FCR) among groups (P>0.05). The viscerosomatic index (VSI) of grass carp in C45 group was significantly higher than that in C0 group (P<0.05). (2) In terms of health status, the albumin and globulin ratio (A/G) of serum in C100 group was significantly lower than that in C0 group (P<0.05), and the activity of serum superoxide dismutase (SOD) in C15 group was significantly higher than that in C0 group (P<0.05); There were no pathological changes in liver and muscle tissue of grass carp in each group. (3) In terms of flesh quality, compared with C0 group, the crude protein content of grass carp muscle in C75 group and the isoleucine content of C30 group increased significantly (P<0.05), the muscle springiness and adhesiveness of grass carp in C30, C45 and C100 groups increased significantly (P<0.05), and the sarcomere length of grass carp muscle in C75 and C100 groups increased significantly (P<0.05). The results showed that CPC can completely replace soybean meal in grass carp diets, improve its immunity and flesh quality.
Open Access
2023, 47(2): 249-256.
DOI: 10.7541/2023.2022.0353
Abstract：
Swamp eel (Monopterus albus) is one of the most important cultured fresh water species with high economic value in China, however, the present compound diets could not meet the growth and gonad development of swamp eel broodstocks, which hampered the large-scaled aquaculture of this species, therefore, the reproduction improvement of swamp eels by optimization of the compound diet formulation is on the urgent need. Antarctic krill meal is rich in sustainable resources and has the same nutritional level as fish meal, which meets the requirements of a new type of animal protein source for feed. Reports showed that Antarctic krill meal inclusion improved the growth and reproduction of several aquatic animals. In this study, two-winter-age female Monopterus albus with an initial body weight of (36.41±3.62) g was adopted. Antarctic krill meal was included to replace 0, 20%, 40%, 60%, 80%, and 100% fish meal to make 6 groups of iso-nitrogenous and iso-energetic diets. After 12 weeks of culture, the growth performance, body composition, hepatic anti-oxidant capacity and non-specific immunity, and fecundity of six groups of experimental eels were determined. The results showed that the weight gain rate (WGR) and specific growth rate (SGR) of eels had no significant differences in 20% replacement group and the control group (P>0.05). However, the further increase of Antarctic krill meal substitution (>40%) led to the growth performance reduction. In muscle, crude protein concentration was higher in 20% substitution group than the other experimental groups; no significant differences were observed in the crude lipid and ash concentrations among different groups in muscle of swamp eels (P>0.05). In ovary, the nutrient composition had no significant difference between groups of 20% substitution group and the control group (P>0.05). Concentrations of crude protein and crude lipid decreased significantly while the moisture concentration increased gradually by Antarctic krill meal substitution from 60% to 100%. The further detection of the anti-oxidant capacity of liver revealed that superoxide dismutase (SOD) activity decreased gradually albeit with the increase of malondialdehyde (MDA) concentration in groups of Antarctic krill meal substitution higher than 40%. The catalase (CAT) activity in 100% substitution group was lower than the other five groups. The following non-specific immunity evaluation of liver suggested that no significant differences were observed between 20% substitution group and the control group in parameters of alkaline phosphatase (AKP), complement 4 (C4), and immunoglobulin M (IgM) (P>0.05). When the Antarctic krill meal substitution level were 60% or higher, the AKP activity showed the increased trend, while concentrations of C4 and IgM decreased instead. Lastly, fecundity of swamp eels in all groups were examined. The 20% Antarctic krill meal substitution did not influence fecundity parameters including gonadosomatic index (GSI), absolute fecundity, relative fecundity and serum estradiol concentration (P>0.05) in swamp eels. GSI in 80% and 100% groups were lower than that of 40% and 60% groups. From 60% to 100% substitution groups, the absolute fecundity, relative fecundity and estradiol concentrations decreased gradually with the increase of Antarctic krill meal inclusion. Egg diameters increased gradually with the increase of krill meal inclusions, but significant differences were only found from 100% group to groups of 0 and 20% (P<0.05). From the above results, it showed that the growth performance, ovarian nutrient composition, hepatic anti-oxidant capacity and non-specific immunity, and fecundity will not be influenced when 20% fish meal were replaced by Antarctic krill meal in diets of female swamp eels. Higher substitutions of Antarctic krill meal will intensify the adverse effect on this fish species. Therefore, the substitution of Antarctic krill meal of fish meal should not exceed 20% in formulated diets of female Monopterus albus.
Swamp eel (Monopterus albus) is one of the most important cultured fresh water species with high economic value in China, however, the present compound diets could not meet the growth and gonad development of swamp eel broodstocks, which hampered the large-scaled aquaculture of this species, therefore, the reproduction improvement of swamp eels by optimization of the compound diet formulation is on the urgent need. Antarctic krill meal is rich in sustainable resources and has the same nutritional level as fish meal, which meets the requirements of a new type of animal protein source for feed. Reports showed that Antarctic krill meal inclusion improved the growth and reproduction of several aquatic animals. In this study, two-winter-age female Monopterus albus with an initial body weight of (36.41±3.62) g was adopted. Antarctic krill meal was included to replace 0, 20%, 40%, 60%, 80%, and 100% fish meal to make 6 groups of iso-nitrogenous and iso-energetic diets. After 12 weeks of culture, the growth performance, body composition, hepatic anti-oxidant capacity and non-specific immunity, and fecundity of six groups of experimental eels were determined. The results showed that the weight gain rate (WGR) and specific growth rate (SGR) of eels had no significant differences in 20% replacement group and the control group (P>0.05). However, the further increase of Antarctic krill meal substitution (>40%) led to the growth performance reduction. In muscle, crude protein concentration was higher in 20% substitution group than the other experimental groups; no significant differences were observed in the crude lipid and ash concentrations among different groups in muscle of swamp eels (P>0.05). In ovary, the nutrient composition had no significant difference between groups of 20% substitution group and the control group (P>0.05). Concentrations of crude protein and crude lipid decreased significantly while the moisture concentration increased gradually by Antarctic krill meal substitution from 60% to 100%. The further detection of the anti-oxidant capacity of liver revealed that superoxide dismutase (SOD) activity decreased gradually albeit with the increase of malondialdehyde (MDA) concentration in groups of Antarctic krill meal substitution higher than 40%. The catalase (CAT) activity in 100% substitution group was lower than the other five groups. The following non-specific immunity evaluation of liver suggested that no significant differences were observed between 20% substitution group and the control group in parameters of alkaline phosphatase (AKP), complement 4 (C4), and immunoglobulin M (IgM) (P>0.05). When the Antarctic krill meal substitution level were 60% or higher, the AKP activity showed the increased trend, while concentrations of C4 and IgM decreased instead. Lastly, fecundity of swamp eels in all groups were examined. The 20% Antarctic krill meal substitution did not influence fecundity parameters including gonadosomatic index (GSI), absolute fecundity, relative fecundity and serum estradiol concentration (P>0.05) in swamp eels. GSI in 80% and 100% groups were lower than that of 40% and 60% groups. From 60% to 100% substitution groups, the absolute fecundity, relative fecundity and estradiol concentrations decreased gradually with the increase of Antarctic krill meal inclusion. Egg diameters increased gradually with the increase of krill meal inclusions, but significant differences were only found from 100% group to groups of 0 and 20% (P<0.05). From the above results, it showed that the growth performance, ovarian nutrient composition, hepatic anti-oxidant capacity and non-specific immunity, and fecundity will not be influenced when 20% fish meal were replaced by Antarctic krill meal in diets of female swamp eels. Higher substitutions of Antarctic krill meal will intensify the adverse effect on this fish species. Therefore, the substitution of Antarctic krill meal of fish meal should not exceed 20% in formulated diets of female Monopterus albus.
Open Access
Abstract：
The apparent digestibility coefficients (ADCs) of Tenebrio molitor meal (TMM), Hermetia illucens meal (HIM), Clostridium autoethanogenum protein (CAP), Methylococcus capsulatus meal (MCM), Chlorella vullgaris meal (CVM), Cottonseed protein concentrate (CPC) and Peruvian fishmeal (PFM) were determined in juvenile hybrid grouper (Epinephelus fuscoguttatus♀×Epinephelus lanceolatu♂). A basal diet (including 50% fishmeal) and seven test diets (700 g/kg of the basal diet and 300 g/kg of each test ingredient) were formulated with 0.1% yttrium oxide (Y2O3) as an inert marker. The juvenile hybrid groupers, with initial average body weight of (9.95±0.50) g, were randomly distributed into 0.3 m³ fiberglass tanks, each tank with 30 fish. The faeces samples were collected twice-daily by siphoning following feeding fish after five days of domestication. The ADCs of dry matter of seven test ingredients were ranked as CVM>TMM=CAP=CPC>HIM=MCM=PFM (P<0.05). CVM showed the highest ADCs of dry matter (DM), crude protein (CP) and most amino acids (including methionine and threonine) except crude lipids (CL), whereas HIM had the relatively lower ADCs of DM, CP and most amino acids except CL. CAP had a higher lysine digestibility than the other six test ingredients, and was only lower than CVM in the ADC of CP. The ADC of DM in PFM was significantly lower than that in CVM (P<0.05), and showed no differences with that in CAP (P>0.05). Besides, PFM showed a lower ADC of CP than the ADCs of CP in CVM, CAP and MCM (P<0.05), and showed a lower ADC of lysine than that in CAP as well as a lower ADC of threonine than those in CAP and CVM (P<0.05). Overall, this study showed the advantage of CVM and CAP among the seven protein sources on the digestibility of feed available in hybrid grouper.
The apparent digestibility coefficients (ADCs) of Tenebrio molitor meal (TMM), Hermetia illucens meal (HIM), Clostridium autoethanogenum protein (CAP), Methylococcus capsulatus meal (MCM), Chlorella vullgaris meal (CVM), Cottonseed protein concentrate (CPC) and Peruvian fishmeal (PFM) were determined in juvenile hybrid grouper (Epinephelus fuscoguttatus♀×Epinephelus lanceolatu♂). A basal diet (including 50% fishmeal) and seven test diets (700 g/kg of the basal diet and 300 g/kg of each test ingredient) were formulated with 0.1% yttrium oxide (Y2O3) as an inert marker. The juvenile hybrid groupers, with initial average body weight of (9.95±0.50) g, were randomly distributed into 0.3 m³ fiberglass tanks, each tank with 30 fish. The faeces samples were collected twice-daily by siphoning following feeding fish after five days of domestication. The ADCs of dry matter of seven test ingredients were ranked as CVM>TMM=CAP=CPC>HIM=MCM=PFM (P<0.05). CVM showed the highest ADCs of dry matter (DM), crude protein (CP) and most amino acids (including methionine and threonine) except crude lipids (CL), whereas HIM had the relatively lower ADCs of DM, CP and most amino acids except CL. CAP had a higher lysine digestibility than the other six test ingredients, and was only lower than CVM in the ADC of CP. The ADC of DM in PFM was significantly lower than that in CVM (P<0.05), and showed no differences with that in CAP (P>0.05). Besides, PFM showed a lower ADC of CP than the ADCs of CP in CVM, CAP and MCM (P<0.05), and showed a lower ADC of lysine than that in CAP as well as a lower ADC of threonine than those in CAP and CVM (P<0.05). Overall, this study showed the advantage of CVM and CAP among the seven protein sources on the digestibility of feed available in hybrid grouper.
Open Access
Abstract：
This experiment was conducted to investigate the effects of dietary black soldier fly (Hermetia illucens) larvae meal on growth performance, non-specific immunity and lipid metabolism of Litopenaeus vannamei. The control diet (FM) contained 25% fishmeal and then 10% (BSF10), 20% (BSF20) and 30% (BSF30) of fishmeal protein were replaced by black soldier fly larvae meal to formulate four isonitrogenous and isolipidic diets. Shrimps with an initial body weight of (0.88±0.01) g were fed four times daily for 7 weeks. Results showed that there were no significant differences in growth performance of shrimp fed BSF10 and BSF20 diets compared to FM group (P>0.05), but the growth performance of the shrimp in the BSF30 group significantly reduced (P<0.05). The whole shrimp crude lipid content was significantly lower in the BSF20 and BSF30 groups, and the hemolymph triglyceride and total cholesterol levels were significantly lower in the BSF30 group compared to FM group (P<0.05), but there were no significantly different in crude lipid of hepatopancreas among the four groups (P>0.05). The activities of hemolymph alanine aminotransferase and aspartate aminotransferase significantly decreased in the BSF10, BSF20 and BSF30 groups compared to FM group (P<0.05). The total antioxidant capacity of BSF20 group was significantly higher than that of the other groups, and superoxide dismutase activity of BSF10 group was significantly higher than that of FM group (P<0.05). The hepatopancreas acid phosphatase and alkaline phosphatase activities were significantly lower in the BSF30 group than that in the FM group (P<0.05). The lipase activity of BSF30 group was significantly lower than BSF10 group (P<0.05). The fatty acid synthase activity in BSF10 and BSF20 groups was significantly higher than that in FM group, the carnitine palmitoyl transferase activity in BSF20 group was significantly higher than the other three groups, and the activity of isocitrate dehydrogenase in BSF30 group was significantly higher than that in FM group (P<0.05). The activities of hemolymph lipid triglyceride lipase and α-ketoglutarate dehydrogenase in BSF10, BSF20 and BSF30 groups were significantly higher than those in FM group (P<0.05). To conclude, replacing 10% or 20% of fishmeal with black soldier fly larvae meal had no negative effect on the growth performance of Litopenaeus vannamei, improved the antioxidant capacity of shrimp and reduced the hemolymph glutamate transaminase and glutamic acid transaminase activities. The crude lipid of whole shrimp significantly reduced in BSF20 group, and when the replacing level reached to 30%, the activity of enzymes related to lipid catabolism and tricarboxylic acid cycle was significantly increased, which further promoted the lipid metabolism of shrimp.
This experiment was conducted to investigate the effects of dietary black soldier fly (Hermetia illucens) larvae meal on growth performance, non-specific immunity and lipid metabolism of Litopenaeus vannamei. The control diet (FM) contained 25% fishmeal and then 10% (BSF10), 20% (BSF20) and 30% (BSF30) of fishmeal protein were replaced by black soldier fly larvae meal to formulate four isonitrogenous and isolipidic diets. Shrimps with an initial body weight of (0.88±0.01) g were fed four times daily for 7 weeks. Results showed that there were no significant differences in growth performance of shrimp fed BSF10 and BSF20 diets compared to FM group (P>0.05), but the growth performance of the shrimp in the BSF30 group significantly reduced (P<0.05). The whole shrimp crude lipid content was significantly lower in the BSF20 and BSF30 groups, and the hemolymph triglyceride and total cholesterol levels were significantly lower in the BSF30 group compared to FM group (P<0.05), but there were no significantly different in crude lipid of hepatopancreas among the four groups (P>0.05). The activities of hemolymph alanine aminotransferase and aspartate aminotransferase significantly decreased in the BSF10, BSF20 and BSF30 groups compared to FM group (P<0.05). The total antioxidant capacity of BSF20 group was significantly higher than that of the other groups, and superoxide dismutase activity of BSF10 group was significantly higher than that of FM group (P<0.05). The hepatopancreas acid phosphatase and alkaline phosphatase activities were significantly lower in the BSF30 group than that in the FM group (P<0.05). The lipase activity of BSF30 group was significantly lower than BSF10 group (P<0.05). The fatty acid synthase activity in BSF10 and BSF20 groups was significantly higher than that in FM group, the carnitine palmitoyl transferase activity in BSF20 group was significantly higher than the other three groups, and the activity of isocitrate dehydrogenase in BSF30 group was significantly higher than that in FM group (P<0.05). The activities of hemolymph lipid triglyceride lipase and α-ketoglutarate dehydrogenase in BSF10, BSF20 and BSF30 groups were significantly higher than those in FM group (P<0.05). To conclude, replacing 10% or 20% of fishmeal with black soldier fly larvae meal had no negative effect on the growth performance of Litopenaeus vannamei, improved the antioxidant capacity of shrimp and reduced the hemolymph glutamate transaminase and glutamic acid transaminase activities. The crude lipid of whole shrimp significantly reduced in BSF20 group, and when the replacing level reached to 30%, the activity of enzymes related to lipid catabolism and tricarboxylic acid cycle was significantly increased, which further promoted the lipid metabolism of shrimp.
Open Access
Abstract：
To evaluate the effects of dietary aflatoxin B1 (AFB1) on growth performance, feed efficiency, and histological changes in juvenile red swamp crayfish (Procambarus clarkii), crayfish with initial body weight of [(0.382±0.005) g] were fed with four diets containing 0, 10, 100 and 1000 μg/kg AFB1 for a 42-day trial. Significant lower survival rate (SR), feeding rate (FR), final body weight (FBW), specific growth rate (SGR) and feed efficiency (FE) were observed in 100 μg/kg and 1000 μg/kg AFB1 group, while no significant differences were found in 10 μg/kg group compared to control group. There were no significant differences in alkaline phosphatase (AKP), alanine aminotransferase (ALT), aspartate, aminotransferase (AST), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione S-transferase (GST) and malondialdehyde (MDA) in hepatopancreas between the control and 10 μg/kg AFB1 group, while significant decrease in superoxide dismutase (SOD) was observed in 10 μg/kg AFB1 group. AFB1 above 100 μg/kg significantly impacted activities of the aforementioned hepatopancreas enzymes. Slight histological changes were identified in hepatopancreas of 10 μg/kg AFB1 group. However, severe lesions of hepatopancreas were found in 100 μg/kg and 1000 μg/kg AFB1 group, which showed decreased numbers of R-cells and increased numbers of B-cells. The ultrastructural results showed that with the increase of AFB1 concentration, hepatopancreas demonstrated swelling mitochondria, expanded rough endoplasmic reticulum, increased cytoplasmic vesicles and larger lipid droplets. No AFB1 residues were detected in whole body when crayfish were fed with AFB1 up to 100 μg/kg, however, tiny dose (1.65 μg/kg) of AFB1 were detected in the group with 1000 μg/kg AFB1, which was below the safety limitation of FDA. In summary, dietary AFB1 above 10 μg/kg had an adverse effect on juvenile crayfish, which indicated that red swamp crayfish was a sensitive species to AFB1.
To evaluate the effects of dietary aflatoxin B1 (AFB1) on growth performance, feed efficiency, and histological changes in juvenile red swamp crayfish (Procambarus clarkii), crayfish with initial body weight of [(0.382±0.005) g] were fed with four diets containing 0, 10, 100 and 1000 μg/kg AFB1 for a 42-day trial. Significant lower survival rate (SR), feeding rate (FR), final body weight (FBW), specific growth rate (SGR) and feed efficiency (FE) were observed in 100 μg/kg and 1000 μg/kg AFB1 group, while no significant differences were found in 10 μg/kg group compared to control group. There were no significant differences in alkaline phosphatase (AKP), alanine aminotransferase (ALT), aspartate, aminotransferase (AST), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione S-transferase (GST) and malondialdehyde (MDA) in hepatopancreas between the control and 10 μg/kg AFB1 group, while significant decrease in superoxide dismutase (SOD) was observed in 10 μg/kg AFB1 group. AFB1 above 100 μg/kg significantly impacted activities of the aforementioned hepatopancreas enzymes. Slight histological changes were identified in hepatopancreas of 10 μg/kg AFB1 group. However, severe lesions of hepatopancreas were found in 100 μg/kg and 1000 μg/kg AFB1 group, which showed decreased numbers of R-cells and increased numbers of B-cells. The ultrastructural results showed that with the increase of AFB1 concentration, hepatopancreas demonstrated swelling mitochondria, expanded rough endoplasmic reticulum, increased cytoplasmic vesicles and larger lipid droplets. No AFB1 residues were detected in whole body when crayfish were fed with AFB1 up to 100 μg/kg, however, tiny dose (1.65 μg/kg) of AFB1 were detected in the group with 1000 μg/kg AFB1, which was below the safety limitation of FDA. In summary, dietary AFB1 above 10 μg/kg had an adverse effect on juvenile crayfish, which indicated that red swamp crayfish was a sensitive species to AFB1.
Open Access
Abstract：
In this study, the cold shock treatment was used to induce triploid yellow drum (Nibea albiflora) and the ploidy was determined. The histology and gene expression analysis of reproduction-related genes were further used to characterize the gonadal development in triploid yellow drum. Firstly, the fertilized eggs were subjected to the cold shock treatment implemented at 3℃ for a period of 10 min commencing at post-fertilization 2.5min, and the fertilization rate and hatching rate in the cold shock treatment groups were (70.31±4.49)% and (21.5±6.63)%, respectively, which were significantly lower than that of diploid. Secondly, we found that the DNA relative content of triploid was 1.5 times larger than that of diploid by flow cytometer analysis, and the number of the chromosome in the triploid was 72, whereas the number of the chromosome in the diploid was 48 shown by karyotype analysis. The rate of the triploid was 100% in the present study. Thirdly, the gonadosomatic indexes of the triploids were significantly lower than that of the diploids. Histological results showed that the gonadal development of the triploids was slower than that of the diploids. At the age of 12 months, the testis and ovary of the diploids were both at the stage Ⅴ, while the testis and ovary of the triploids were at stage Ⅲ and stage Ⅰ, respectively. Fourthly, the dmrt1 and vasa expression in the triploid testis and cyp19a expression in the triploid ovary were significantly lower than those in the diploid gonads (P<0.05), and the vasa expression in the triploid ovary was also lower than that in the diploids (P>0.05). The results indicated that the triploid yellow drum could be successfully induced by the cold shock treatment, and the gonadal development of the triploids was retarded. The results of present study will lay a basis for the application of the triploid in germ cell transplantation and the genetic improvement of yellow drum.
In this study, the cold shock treatment was used to induce triploid yellow drum (Nibea albiflora) and the ploidy was determined. The histology and gene expression analysis of reproduction-related genes were further used to characterize the gonadal development in triploid yellow drum. Firstly, the fertilized eggs were subjected to the cold shock treatment implemented at 3℃ for a period of 10 min commencing at post-fertilization 2.5min, and the fertilization rate and hatching rate in the cold shock treatment groups were (70.31±4.49)% and (21.5±6.63)%, respectively, which were significantly lower than that of diploid. Secondly, we found that the DNA relative content of triploid was 1.5 times larger than that of diploid by flow cytometer analysis, and the number of the chromosome in the triploid was 72, whereas the number of the chromosome in the diploid was 48 shown by karyotype analysis. The rate of the triploid was 100% in the present study. Thirdly, the gonadosomatic indexes of the triploids were significantly lower than that of the diploids. Histological results showed that the gonadal development of the triploids was slower than that of the diploids. At the age of 12 months, the testis and ovary of the diploids were both at the stage Ⅴ, while the testis and ovary of the triploids were at stage Ⅲ and stage Ⅰ, respectively. Fourthly, the dmrt1 and vasa expression in the triploid testis and cyp19a expression in the triploid ovary were significantly lower than those in the diploid gonads (P<0.05), and the vasa expression in the triploid ovary was also lower than that in the diploids (P>0.05). The results indicated that the triploid yellow drum could be successfully induced by the cold shock treatment, and the gonadal development of the triploids was retarded. The results of present study will lay a basis for the application of the triploid in germ cell transplantation and the genetic improvement of yellow drum.
Open Access
2023, 47(2): 298-307.
DOI: 10.7541/2023.2022.0095
Abstract：
In vertebrate embryos, gastrulation is the fundamental morphogenetic movements. It leads to the formation of the basic germ layers and the body axis. During gastrulation, convergence and extension (CE) movements narrow a group of cells mediolaterally and lengthen them to facilitate the elongation of the anteroposterior axis. In this process, the planar cell polarity (PCP) pathway, also called the noncanonical Wnt signaling pathway, is of particular importance to control CE movements. However, the precise cellular and molecular mechanisms underlying this process remains to be further studied. Rspo1 (R-spondin 1) is a secreted protein that has been implicated in activating the Wnt/β-catenin signaling levels with Wnt ligands, through which Rspo1 promotes angiogenesis and specifies hematopoietic stem cells, as well as promotes female development. Recently, it was reported that Rspo1 exhibits Wnt/β-catenin independent roles. For example, Rspo1-Lgr4-cAMP-Erα axis regulates estrogen receptor expression, and RSPO1-LGR5 activates TGFβ signaling in colon cancer. Given the complex role of Rspo1, we speculate that Rspo1 is involved in the early embryonic development. To investigate the developmental role of Rspo1 in zebrafish embryos, we examined the spatiotemporal expression pattern of rspo1 using RT-PCR and whole-mount in situ hybridization. The results showed that rspo1 mRNA is maternally deposited and expresses ubiquitously in early embryonic stages before 12hpf (hours post fertilization), implying that Rspo1 may play an important role in the regulation of embryonic development. Next, we carried out gain-of-function and loss-of function analysis of Rspo1. The results showed that either overexpression or knockdown of rspo1 abrogates the CE movements during gastrulation. In order to explore whether rspo1 affects CE movement by participating in Wnt/PCP signaling pathway, we used AP-1 luciferase reporter to monitor Wnt/PCP in zebrafish embryos. The results showed that forced expression of rspo1 decreases but knockdown of rspo1 increases Wnt/PCP signaling reporter activity, indicating that Rspo1 inhibits Wnt/PCP signaling pathway. Consistent with this result, the phosphorylated-JNK levels, an indicator of activity of Wnt/PCP signaling pathway, dramatically increased in rspo1 morphant embryos at gastrulation stage. Further analyses indicate that coinjection of rspo1 mRNA and dnJNK (Dominant negative JNK) mRNA, or coinjection of rspo1 MOs and wnt11/wnt5b mRNA synergistically enhanced CE defects. Taken together, these results suggest that Rspo1 regulates CE movements during gastrulation by negatively regulating the Wnt/PCP signaling in zebrafish embryos. Overall, our studies will provide novel insights into the regulation of Wnt/PCP signaling in vertebrates.
In vertebrate embryos, gastrulation is the fundamental morphogenetic movements. It leads to the formation of the basic germ layers and the body axis. During gastrulation, convergence and extension (CE) movements narrow a group of cells mediolaterally and lengthen them to facilitate the elongation of the anteroposterior axis. In this process, the planar cell polarity (PCP) pathway, also called the noncanonical Wnt signaling pathway, is of particular importance to control CE movements. However, the precise cellular and molecular mechanisms underlying this process remains to be further studied. Rspo1 (R-spondin 1) is a secreted protein that has been implicated in activating the Wnt/β-catenin signaling levels with Wnt ligands, through which Rspo1 promotes angiogenesis and specifies hematopoietic stem cells, as well as promotes female development. Recently, it was reported that Rspo1 exhibits Wnt/β-catenin independent roles. For example, Rspo1-Lgr4-cAMP-Erα axis regulates estrogen receptor expression, and RSPO1-LGR5 activates TGFβ signaling in colon cancer. Given the complex role of Rspo1, we speculate that Rspo1 is involved in the early embryonic development. To investigate the developmental role of Rspo1 in zebrafish embryos, we examined the spatiotemporal expression pattern of rspo1 using RT-PCR and whole-mount in situ hybridization. The results showed that rspo1 mRNA is maternally deposited and expresses ubiquitously in early embryonic stages before 12hpf (hours post fertilization), implying that Rspo1 may play an important role in the regulation of embryonic development. Next, we carried out gain-of-function and loss-of function analysis of Rspo1. The results showed that either overexpression or knockdown of rspo1 abrogates the CE movements during gastrulation. In order to explore whether rspo1 affects CE movement by participating in Wnt/PCP signaling pathway, we used AP-1 luciferase reporter to monitor Wnt/PCP in zebrafish embryos. The results showed that forced expression of rspo1 decreases but knockdown of rspo1 increases Wnt/PCP signaling reporter activity, indicating that Rspo1 inhibits Wnt/PCP signaling pathway. Consistent with this result, the phosphorylated-JNK levels, an indicator of activity of Wnt/PCP signaling pathway, dramatically increased in rspo1 morphant embryos at gastrulation stage. Further analyses indicate that coinjection of rspo1 mRNA and dnJNK (Dominant negative JNK) mRNA, or coinjection of rspo1 MOs and wnt11/wnt5b mRNA synergistically enhanced CE defects. Taken together, these results suggest that Rspo1 regulates CE movements during gastrulation by negatively regulating the Wnt/PCP signaling in zebrafish embryos. Overall, our studies will provide novel insights into the regulation of Wnt/PCP signaling in vertebrates.
Open Access
Abstract：
Tumor necrosis factor receptor (TNFR)-associated factor 3 (TRAF3) is a highly versatile regulator in many immune pathways, including TNFR and Toll-like receptor (TLRs)/RIG-I-like receptors (RLRs) signal pathway. In this study, a TRAF3 gene was cloned from Oreochromis niloticus (named OnTRAF3), (GenBank No. MN258118), which contained a RING finger, a zinc finger, a coiled-coil and MATH domain. Multiple sequence alignment showed that OnTRAF3 shares a relatively high identity with other known TRAF3 proteins. Quantitative real-time PCR (qRT-PCR) analysis showed OnTRAF3 transcripts were highly expressed in brain, skin, intestine and gill, and it could be induced by Streptococcus agalactiae. In HEK293T cells, OnTRAF3 presented both in the cytoplasm and nucleus. In addition, wide type (WT) OnTRAF3, activated NF-κB signal significantly, RING or Zinc finger was important for this activation. This study provides significant insights into the functions of TRAF3 in tilapia.
Tumor necrosis factor receptor (TNFR)-associated factor 3 (TRAF3) is a highly versatile regulator in many immune pathways, including TNFR and Toll-like receptor (TLRs)/RIG-I-like receptors (RLRs) signal pathway. In this study, a TRAF3 gene was cloned from Oreochromis niloticus (named OnTRAF3), (GenBank No. MN258118), which contained a RING finger, a zinc finger, a coiled-coil and MATH domain. Multiple sequence alignment showed that OnTRAF3 shares a relatively high identity with other known TRAF3 proteins. Quantitative real-time PCR (qRT-PCR) analysis showed OnTRAF3 transcripts were highly expressed in brain, skin, intestine and gill, and it could be induced by Streptococcus agalactiae. In HEK293T cells, OnTRAF3 presented both in the cytoplasm and nucleus. In addition, wide type (WT) OnTRAF3, activated NF-κB signal significantly, RING or Zinc finger was important for this activation. This study provides significant insights into the functions of TRAF3 in tilapia.
Open Access
2023, 47(2): 316-322.
DOI: 10.7541/2023.2022.0131
Abstract：
To study the characteristics of mtf-1 gene of Siniperca chuatsi and the effects of cadmium stress on the circadian rhythm of mtf-1 gene in brain, we analyzed cis-regulatory elements of mtf-1 gene promoter, sequence characteristics and tissues expression patterns of mtf-1 gene, and explored the circadian rhythm changes of mtf-1 gene expression in brain of Siniperca chuatsi under cadmium stress. The results showed that there were binding sites of zinc finger proteins including ZNF136, ZNF384 and ZNF143 in the mtf-1 promoter of S. chuatsi, indicating that their expression is potentially regulated by metal ions. In addition, RORβ binding sites of the core clock gene were also found in the mtf-1 promoter of S. chuatsi, indicating that the mtf-1 gene is potentially involved in circadian rhythm regulation. The analysis of function domain indicated that mtf-1 gene has a highly conserved DNA binding domain and a non-conserved trans-activation domain. mtf-1 gene is expressed in different tissues of S. chuatsi, among which the highest expression level is found in brain tissue, followed by kidney. Under natural conditions, mtf-1 gene showed a trend of high expression at night and low expression in the brain at day. The expression peak phase occurs at ZT 12.65h (nightfall), which is consistent with its life habits. Under cadmium stress, the mtf-1 gene in the brain of S. chuatsi presented continuous low expression level, and with no significant difference between day and night, indicating that the mtf-1 gene expression in the brain of S. chuatsi could be significantly inhibited by cadmium, and the circadian rhythm of mtf-1 in the brain tissue of S. chuatsi is damaged.
To study the characteristics of mtf-1 gene of Siniperca chuatsi and the effects of cadmium stress on the circadian rhythm of mtf-1 gene in brain, we analyzed cis-regulatory elements of mtf-1 gene promoter, sequence characteristics and tissues expression patterns of mtf-1 gene, and explored the circadian rhythm changes of mtf-1 gene expression in brain of Siniperca chuatsi under cadmium stress. The results showed that there were binding sites of zinc finger proteins including ZNF136, ZNF384 and ZNF143 in the mtf-1 promoter of S. chuatsi, indicating that their expression is potentially regulated by metal ions. In addition, RORβ binding sites of the core clock gene were also found in the mtf-1 promoter of S. chuatsi, indicating that the mtf-1 gene is potentially involved in circadian rhythm regulation. The analysis of function domain indicated that mtf-1 gene has a highly conserved DNA binding domain and a non-conserved trans-activation domain. mtf-1 gene is expressed in different tissues of S. chuatsi, among which the highest expression level is found in brain tissue, followed by kidney. Under natural conditions, mtf-1 gene showed a trend of high expression at night and low expression in the brain at day. The expression peak phase occurs at ZT 12.65h (nightfall), which is consistent with its life habits. Under cadmium stress, the mtf-1 gene in the brain of S. chuatsi presented continuous low expression level, and with no significant difference between day and night, indicating that the mtf-1 gene expression in the brain of S. chuatsi could be significantly inhibited by cadmium, and the circadian rhythm of mtf-1 in the brain tissue of S. chuatsi is damaged.
Open Access
2023, 47(2): 323-331.
DOI: 10.7541/2022.2021.0308
Abstract：
Artemia is not only one of the most important live feed for larvi culture, but also an ideal experimental organism for scientific research. Female Artemia produce either nauplii via ovoviviparous pathway or diapause cyst via oviparous pathway. In order to reveal the mechanism of different reproductive modes of Artemia, the reproductive differential transcriptomes of parthenogenetic Artemia were constructed, bioinformatics analysis were performed to screen reproductive differential expression genes, and the gene expression patterns were studied by using qRT-PCR. Transcriptome analysis showed that there were 1452 differentially expressed genes, of which 601 genes were up-regulated and 851 down-regulated in the abscising carpopodium. According to GO function classification, 1243306 and 530 unigene were annotated into biological process, cell composition and molecular function respectively. KEGG enrichment analysis showed that differential genes were significantly enriched in antigen processing and ribosome pathways. Combined with transcriptome data and qRT-PCR analysis, six reproductive-related genes were screened and verified. The results showed that all the six reproductive-related genes had higher expression in oviparous Artemia than in ovoviviparous Artemia. In addition, the conserved domains of the proteins encoded by six candidate reproductive related genes were predicted and phylogenetic trees were constructed respectively. The results showed that the protein domains were consistent with the previously reported reproductive genes. Over all, our study indicated that the selected six genes may influence the reproductive process of Artemia. This study provides valuable information for dissecting the molecular mechanism of reproductive pattern in the parthenogenetic Artemia, and may also help to refine the reproductive biological theory of Artemia.
Artemia is not only one of the most important live feed for larvi culture, but also an ideal experimental organism for scientific research. Female Artemia produce either nauplii via ovoviviparous pathway or diapause cyst via oviparous pathway. In order to reveal the mechanism of different reproductive modes of Artemia, the reproductive differential transcriptomes of parthenogenetic Artemia were constructed, bioinformatics analysis were performed to screen reproductive differential expression genes, and the gene expression patterns were studied by using qRT-PCR. Transcriptome analysis showed that there were 1452 differentially expressed genes, of which 601 genes were up-regulated and 851 down-regulated in the abscising carpopodium. According to GO function classification, 1243306 and 530 unigene were annotated into biological process, cell composition and molecular function respectively. KEGG enrichment analysis showed that differential genes were significantly enriched in antigen processing and ribosome pathways. Combined with transcriptome data and qRT-PCR analysis, six reproductive-related genes were screened and verified. The results showed that all the six reproductive-related genes had higher expression in oviparous Artemia than in ovoviviparous Artemia. In addition, the conserved domains of the proteins encoded by six candidate reproductive related genes were predicted and phylogenetic trees were constructed respectively. The results showed that the protein domains were consistent with the previously reported reproductive genes. Over all, our study indicated that the selected six genes may influence the reproductive process of Artemia. This study provides valuable information for dissecting the molecular mechanism of reproductive pattern in the parthenogenetic Artemia, and may also help to refine the reproductive biological theory of Artemia.
Open Access
2023, 47(2): 332-338.
DOI: 10.7541/2022.2021.0214
Abstract：
The winged pearl oyster, Pteria penguin, is a widely distributed large pearl oyster species, which can produce large-sized mabé (half-pearl), and exhibit strong tolerance to severe environment. However, genetic improvement of P. penguin was still in its infancy. In this study, the correlation between five microsatellite loci and four growth traits (shell height, shell length, shell width and total weight) of 500 winged pearl oysters were analyzed by One-way ANOVA. Multiple comparisons between different genotypes of microsatellite markers and growth traits were performed. It was shown that the 5 loci in this study are all highly polymorphic loci, among which, QEB-D15 and CL-232 were extremely significantly associated with the shell width of the winged pearl oyster (P<0.01). The individuals with genotype 239/263 and 239/273 at QEB-D15 had the maximum and the minimum shell width, respectively. The 263 bp allele might positively correlate with the shell width, while the 273 bp allele might negatively correlate with the shell width. The average values of shell length, shell width and total weight of individuals with genotype 157/174 at locus CL-232 were larger than that of other genotypes, suggested that this genotype was the dominant genotype. Individuals with genotype of 177/192 at locus CL-232 had the smallest shell length, shell width, shell height and total weight, indicated that the 177/192 may be an inferior genotype. In addition, the shell width is correlated with two SSR loci, which indicates that the shell width is a phenotypic trait that may not be controlled by a single gene. This study could provide valuable information for molecular marker-assisted selection of P. penguin.
The winged pearl oyster, Pteria penguin, is a widely distributed large pearl oyster species, which can produce large-sized mabé (half-pearl), and exhibit strong tolerance to severe environment. However, genetic improvement of P. penguin was still in its infancy. In this study, the correlation between five microsatellite loci and four growth traits (shell height, shell length, shell width and total weight) of 500 winged pearl oysters were analyzed by One-way ANOVA. Multiple comparisons between different genotypes of microsatellite markers and growth traits were performed. It was shown that the 5 loci in this study are all highly polymorphic loci, among which, QEB-D15 and CL-232 were extremely significantly associated with the shell width of the winged pearl oyster (P<0.01). The individuals with genotype 239/263 and 239/273 at QEB-D15 had the maximum and the minimum shell width, respectively. The 263 bp allele might positively correlate with the shell width, while the 273 bp allele might negatively correlate with the shell width. The average values of shell length, shell width and total weight of individuals with genotype 157/174 at locus CL-232 were larger than that of other genotypes, suggested that this genotype was the dominant genotype. Individuals with genotype of 177/192 at locus CL-232 had the smallest shell length, shell width, shell height and total weight, indicated that the 177/192 may be an inferior genotype. In addition, the shell width is correlated with two SSR loci, which indicates that the shell width is a phenotypic trait that may not be controlled by a single gene. This study could provide valuable information for molecular marker-assisted selection of P. penguin.
Open Access
2023, 47(2): 339-344.
DOI: 10.7541/2023.2022.0038
Abstract：
At present, there are few researches on the pearl breeding mechanism of the high-quality freshwater mussel Hyriopsis schlegelii, and the Pif gene is closely related to the formation of shellfish pearls. In order to explore the preliminary function of Pif gene of Hyriopsis schlegelii, the full-length cDNA sequence of Pif gene was obtained for the first time in Hyriopsis schlegelii by RACE-PCR technique, which is named HsPif. The full-length untranslated region (5'UTR) of 5'- terminal untranslated region of Pif gene was 485 bp, 3' untranslated region (3'UTR) and 363 bp, open reading frame (ORF) 3072 bp, which encodes a total of 1023 amino acids. It was speculated that the bioinformatics analysis of two proteins encoding HsPif97 and HsPif80 showed that HsPif protein contained one von-Willebrand factor A (VWA) domain and three chitin binding domains (ChtBD2). The results of amino acid composition showed that the content of aspartic acid was the highest, accounting for 12.5%, and the content of histidine was the lowest, accounting for 1.32%. The α helix content in the protein secondary structure accounted for 19.63%, the irregular crimp accounted for 55.09%, and the extension chain accounted for 16.86%. The hydrophilic index of HsPif protein was –0.566. Phylogenetic tree analysis showed that HsPif and Hyriopsis cumingii Pif were the most conservative in one branch and on the same large branch as other shellfish. The results of tissue fluorescence quantitative PCR showed that HsPif gene was mainly expressed in the mantle, and in situ hybridization showed that the hybridization reaction mainly occurred in the mantle epithelial cells. The changes of HsPif gene expression were detected by qPCR after grafting. The results showed that HsPif gene expression changed with the development of pearl sac. The expression level of HsPif gene decreased significantly on the 7th and 90th day after nuclear insertion, and significantly increased on the 15th, 60th and 120th day. There was no significant change between the 30th day and the control group. The above experimental results suggest that HsPif gene may be related to the secretion and formation of pearls, which is helpful to further understand the mechanism of pearl formation and provide reference for pearl culture.
At present, there are few researches on the pearl breeding mechanism of the high-quality freshwater mussel Hyriopsis schlegelii, and the Pif gene is closely related to the formation of shellfish pearls. In order to explore the preliminary function of Pif gene of Hyriopsis schlegelii, the full-length cDNA sequence of Pif gene was obtained for the first time in Hyriopsis schlegelii by RACE-PCR technique, which is named HsPif. The full-length untranslated region (5'UTR) of 5'- terminal untranslated region of Pif gene was 485 bp, 3' untranslated region (3'UTR) and 363 bp, open reading frame (ORF) 3072 bp, which encodes a total of 1023 amino acids. It was speculated that the bioinformatics analysis of two proteins encoding HsPif97 and HsPif80 showed that HsPif protein contained one von-Willebrand factor A (VWA) domain and three chitin binding domains (ChtBD2). The results of amino acid composition showed that the content of aspartic acid was the highest, accounting for 12.5%, and the content of histidine was the lowest, accounting for 1.32%. The α helix content in the protein secondary structure accounted for 19.63%, the irregular crimp accounted for 55.09%, and the extension chain accounted for 16.86%. The hydrophilic index of HsPif protein was –0.566. Phylogenetic tree analysis showed that HsPif and Hyriopsis cumingii Pif were the most conservative in one branch and on the same large branch as other shellfish. The results of tissue fluorescence quantitative PCR showed that HsPif gene was mainly expressed in the mantle, and in situ hybridization showed that the hybridization reaction mainly occurred in the mantle epithelial cells. The changes of HsPif gene expression were detected by qPCR after grafting. The results showed that HsPif gene expression changed with the development of pearl sac. The expression level of HsPif gene decreased significantly on the 7th and 90th day after nuclear insertion, and significantly increased on the 15th, 60th and 120th day. There was no significant change between the 30th day and the control group. The above experimental results suggest that HsPif gene may be related to the secretion and formation of pearls, which is helpful to further understand the mechanism of pearl formation and provide reference for pearl culture.
Open Access
2023, 47(2): 345-354.
DOI: 10.7541/2023.2022.0061
Abstract：
Dactylogyrus species has high pathogenicity to the goldfish (Carassius auratus). In order to investigate the species of Dactylogyrus, we identified specimens of dactylogyrids collected from gills of the goldfish in Liangzi Lake, Hubei Province, based on morphological and molecular data in the present study. There were seven Dactylogyrus species, including D. vastator, D. intermedius, D. arcuatus, D. baueri, D. formosus, D. inexpeatatus and D. dulkeiti. The morphometric characteristics of sclerotized parts of the opisthaptor in these dactylogyrids were measured and redescribed. D. intermedius, D. formosus and D. dulkeiti were identified by the higher than 99.0% similarities of 18S+ITS1+5.8S partial sequences to the related Dactylogyrus species from the GenBank. The sequence of D. arcuatus was obtained for the first time. However, the sequence similarity between D. vastator and the related Dactylogyrus species from the GenBank was only 96.37%. In addition, high Kimura-two-parameter genetic distances (0.004—0.058) were detected among D. vastator using partial 18S rDNA and ITS1 sequences, but lower than the interspecific variability (0.046—0.064) between D. vastator and D. intermedius. In the present study, the morphological characteristics of Dactylogyrus were redescribed comprehensively and molecular classification markers were sequenced, which provided the basic data and a reference for the identification of Dactylogyrus species on the gills of the goldfish.
Dactylogyrus species has high pathogenicity to the goldfish (Carassius auratus). In order to investigate the species of Dactylogyrus, we identified specimens of dactylogyrids collected from gills of the goldfish in Liangzi Lake, Hubei Province, based on morphological and molecular data in the present study. There were seven Dactylogyrus species, including D. vastator, D. intermedius, D. arcuatus, D. baueri, D. formosus, D. inexpeatatus and D. dulkeiti. The morphometric characteristics of sclerotized parts of the opisthaptor in these dactylogyrids were measured and redescribed. D. intermedius, D. formosus and D. dulkeiti were identified by the higher than 99.0% similarities of 18S+ITS1+5.8S partial sequences to the related Dactylogyrus species from the GenBank. The sequence of D. arcuatus was obtained for the first time. However, the sequence similarity between D. vastator and the related Dactylogyrus species from the GenBank was only 96.37%. In addition, high Kimura-two-parameter genetic distances (0.004—0.058) were detected among D. vastator using partial 18S rDNA and ITS1 sequences, but lower than the interspecific variability (0.046—0.064) between D. vastator and D. intermedius. In the present study, the morphological characteristics of Dactylogyrus were redescribed comprehensively and molecular classification markers were sequenced, which provided the basic data and a reference for the identification of Dactylogyrus species on the gills of the goldfish.
Open Access
2023, 47(2): 355-364.
DOI: 10.7541/2022.2021.0324
Abstract：
Neurobehavioral toxicity is one of important research fields in neuroscience, neuropharmacology and neurotoxicology, which of growing importance for understanding the mechanisms of chemicals on nervous system and for evaluating the quality of ecosystem. Possessing well-developed central nervous system, fish is extremely sensitive to chemicals in the water environment, and the nervous system can produce a comprehensive and coordinated response to various stimuli, which resulted in complex, well-characterized behaviors, including its swimming behaviors and social behaviors. And fish behavior is now recognized as a complex, homologous to mammals, context specific, adaptive and highly variable. A variety of behavioral tests have been developed to assess motor function, stress response, social behavior and learning/memory in fish. And behavior of fish can be measured to determine the functional impact of chemicals. The elementary actions of a neurotoxicant can be followed in terms of disruptions of neural differentiation, proliferation, migration, outgrowth, synapse formation, and circuit development. Fish has been widely used as a tool to detect toxins in water samples and to investigate the mechanisms of action of environmental toxins and their related diseases in recent years. Fish offer many advantages that complement classic mammalian models for the study of normal development as well as for neurobehavioral effects of exposure to chemicals. Fish provide a key intermediate model of neurobehavioral toxicity between high throughput in vitro cell-based assays and the classic mammalian models as they have the accessibility of in vitro models and the complex functional capabilities of mammalian models. The present article reviews recent research progress on neurobehavioral toxicology studies using fish as a model, and we present and discuss the neurobehavioral toxicity of typical pollutants (microplastics and toxins absorbed to microplastics, organic pollutants, et al.) and drugs (alcohol, caffeine, benzodiazepines, selective serotonin reuptake inhibitors, et al.) on fish. And future research directions are proposed. The article is expected to provide a reference for researchers in neurobehavioral toxicity and its application.
Neurobehavioral toxicity is one of important research fields in neuroscience, neuropharmacology and neurotoxicology, which of growing importance for understanding the mechanisms of chemicals on nervous system and for evaluating the quality of ecosystem. Possessing well-developed central nervous system, fish is extremely sensitive to chemicals in the water environment, and the nervous system can produce a comprehensive and coordinated response to various stimuli, which resulted in complex, well-characterized behaviors, including its swimming behaviors and social behaviors. And fish behavior is now recognized as a complex, homologous to mammals, context specific, adaptive and highly variable. A variety of behavioral tests have been developed to assess motor function, stress response, social behavior and learning/memory in fish. And behavior of fish can be measured to determine the functional impact of chemicals. The elementary actions of a neurotoxicant can be followed in terms of disruptions of neural differentiation, proliferation, migration, outgrowth, synapse formation, and circuit development. Fish has been widely used as a tool to detect toxins in water samples and to investigate the mechanisms of action of environmental toxins and their related diseases in recent years. Fish offer many advantages that complement classic mammalian models for the study of normal development as well as for neurobehavioral effects of exposure to chemicals. Fish provide a key intermediate model of neurobehavioral toxicity between high throughput in vitro cell-based assays and the classic mammalian models as they have the accessibility of in vitro models and the complex functional capabilities of mammalian models. The present article reviews recent research progress on neurobehavioral toxicology studies using fish as a model, and we present and discuss the neurobehavioral toxicity of typical pollutants (microplastics and toxins absorbed to microplastics, organic pollutants, et al.) and drugs (alcohol, caffeine, benzodiazepines, selective serotonin reuptake inhibitors, et al.) on fish. And future research directions are proposed. The article is expected to provide a reference for researchers in neurobehavioral toxicity and its application.
