论文部分内容阅读
源自DEAD-box家族的Vasa基因是生殖细胞的分子标记之一。本研究克隆了七彩神仙鱼(Symphysodon haraldi)Vasa基因的全长序列,并进行了不同组织的表达分析。结果表明:七彩神仙鱼Vasa基因c DNA序列共2 370 bp,其中5’UTR占123 bp,3’UTR为279 bp,ORF编码655个氨基酸,长1 968 bp。氨基酸序列同源性分析表明七彩神仙鱼的Vasa基因与尼罗罗非鱼(Oreochromis niloticus)的同源性最高。半定量分析表明,Vasa基因在成熟七彩神仙鱼的性腺中特异表达,在其它组织中无表达信号。qRT-PCR结果显示,Vasa在七彩神仙鱼早期胚胎发育阶段及出膜后50日内均有表达。在受精卵至囊胚期阶段,Vasa基因表达持续增加,在囊胚期至孵化期阶段,表达持续降低。在仔鱼阶段,Vasa分别在25日龄和40日龄出现了最低和最高表达量。繁殖前后比较发现,繁殖前的精巢组织中Vasa表达量比繁殖后的表达量低,而卵巢恰好相反。本研究结果可为研究七彩神仙鱼的性分化、生殖细胞分子标记及其发育提供参考。
The Vasa gene from the DEAD-box family is one of the molecular markers of germ cells. In this study, the full-length sequence of Vasa gene of Symphysodon haraldi was cloned and analyzed in different tissues. The results showed that there were 2 370 bp DNA sequences of Vasa gene in C. anglica, 123 bp in 5’UTR, 279 bp in 3’UTR, 655 amino acids in ORF, and 1 968 bp in length. Amino acid sequence homology analysis indicated that the Vasa gene of C. aquila had the highest homology with Oreochromis niloticus. Semi-quantitative analysis showed that the Vasa gene was specifically expressed in the gonad of the mature discus fish and no signal was expressed in other tissues. The result of qRT-PCR showed that Vasa was expressed in the early stage of embryonic development and within 50 days after outflow. Vasa gene expression continued to increase from fertilized egg to blastocyst stage, and continued to decline from blastocyst stage to hatch stage. At larval stage, Vasa showed the lowest and highest expression levels at 25 and 40 days of age, respectively. Before and after breeding found that the pre-breeding testes in the Vasa expression level than after breeding low expression, while ovarian exactly the opposite. The results of this study can provide reference for the study of sexual differentiation, germ cell molecular markers and their development.