银鲫pou2基因在胚胎发育过程中的时空表达图式

TEMPORAL AND SPATIAL EXPRESSION PATTERN OF GIBEL CARP POU2 GENE DURING EMBRYOGENESIS

  • 摘要: 用RACE-PCR方法从原肠期SMART文库中扩增到银鲫pou2基因的全长cDNA,其全长为2421bp,开放阅读框为1416bp,编码471个氨基酸,与斑马鱼pou2基因的氨基酸序列一致性高达91.0%。我们用RT-PCR和整体原位杂交的方法研究了银鲫pou2基因在胚胎发育过程中的时空表达图式。RT-PCR结果显示,银鲫pou2基因有母源转录本,其合子基因在高囊胚期强烈表达,在50%下包期和90%下包期也有高量的转录本,但在100%下包期表达量急剧降低,至体节期时已经完全检测不到其转录本。胚胎整体原位杂交结果显示其母源转录本在所有的胚盘细胞中。在高囊胚期和50%下包期,高度表达的合子转录本仍在所有的胚盘细胞中,但至90%下包期时,pou2的表达向胚胎背部的正中线汇聚,集中在神经板的两侧区域和脑部的两条横向条带。在100%下包期时,pou2的表达集中在神经板的中间区域以及预期形成的中后脑区域。至体节期时,转录本消失,这与RT-PCR结果高度一致。银鲫pou2基因的表达图式提示该基因在胚胎发育的早期具有重要作用,它可能参与调控神经板的形成和中后脑细胞的发育命运。

     

    Abstract: Fulllength cDNAof Gibel carp pougene was cloned from gastrula SMART cDNA library through RACE2PCR1 It consists of 2421bp, with an ORF of 1416 bp encoding a protein of 471aa1 The complete amino acid sequence shares 9110% identity with zebrafish pougene product1 Temporal and spatial expression pattern of gibel carp pouduring embryogenesis was investi gated by RT2PCR and whole mount in situ hybridization1 RT-PCR result indicates that there is maternal transcript of gibel carp pou in early embryos and the zygotic pou-transcript is abundantly expressed from blastula stage1 Large amount of pou-transcript is detected at both 50% and 90% epiboly stages1 At 100% epiboly stage, however, the pou-transcript reduces rapidly and disappears at the later embryogenesis1 Whole mount in situ hybridization shows that the maternal transcript ubiquitously exists in all blastomere cells1 In blastula embryos and 50% epiboly embryos, the zygotic pou-transcript is also distributed in every blastomere cell1 At the stage of 90% epiboly, expression of pou-converges to the dorsal midline of embryos and locates in two waves of lateral neural plate and two transverse stripes in the brain region1 In embryos at 100% epiboly, pou-transcript is restricted in the neural plate and areas of presumptive midbrain and hindbrain1 From somite stage, gibel carp poucan not be detected any more, which is consistent with the RT2PCR result1 The expression pattern of gibel carp pou-suggests that this gene should play an important role during early stages of embryogenesis1 It might regulate the formation of neural plate and the fate of midbrain and hindbrain cells during early embryogenesis1

     

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