【作者】 陈云贵；

【导师】 宋平；

【作者基本信息】 武汉大学 ， 动物学， 2005， 硕士

【摘要】 vasa基因和nanos基因在生殖细胞中特异表达。在脊椎动物中它们是原始生殖细胞的迁移和分化所必不可少的。vasa基因是DEAD-box家族的重要成员,其蛋白具有依赖ATP的RNA解旋酶活性。nanos基因编码一个具有锌指结构的蛋白,在生殖干细胞全能性调控方面起着重要作用。探讨这些基因在配子发生过程中的表达和功能具有重要意义。 本文采用原位杂交的方法分别分析了金鱼vasa基因和斑马鱼nanos基因在配子发生过程中的表达。结果表明:在金鱼卵子发生中,在各个时期的卵母细胞的胞质中均有金鱼vasa RNA的杂交信号表达。在Ⅰ、Ⅱ期卵母细胞中vasa RNA的杂交信号强烈,均匀地分布在整个胞质。随着卵母细胞的生长发育及卵黄的积累,Ⅲ、Ⅳ期卵母细胞胞质中vasa RNA的杂交信号急剧减弱,而外周皮层区域,其阳性信号仍较强。在金鱼精子发生中,在精原细胞和初级精母细胞中可检测到金鱼vasa RNA杂交信号,后者的阳性信号比前者微弱;而精子细胞中没有阳性信号。 在斑马鱼卵子发生中,nanosl mRNA均匀分布于卵原细胞和各时期卵母细胞的胞质中;在卵原细胞和Ⅰ、Ⅱ期卵母细胞中,nanosl mRNA的杂交信号十分强烈,而较晚期卵母细胞中信号明显减弱。在斑马鱼精子发生中,nanoslmRNA可在精原细胞和初级精母细胞中检测到。在精原细胞中,nanosl mRNA的阳性信号极为强烈,初级精母细胞中信号较为微弱,精子细胞中未检测到阳性信号。更多还原

【Abstract】 The vasa gene and nanos gene are both specifically expressed in germ cell line. They are essential for the differentiation and migration of primordial germ cell in vertebrates. The vasa gene is an important member in DEAD-box protein family, the Vasa protein is an ATP-dependent RNA helicase. The nanos gene encodes a Zinger-finger protein, it plays critical role in maintaining the totipotency of germline stem cells. It is particularly important to study the expression and function of these gene in gametogenesis.Using in situ hybridization with DIG antisense RNA probe, we detected the expression and distributing of goldfish(Carassius auratus) DEAD-box family gene vasa and gene nanosl of zebrafish during oogenesis and spermatogenesis.The results showed that during oogenesis, the positive signals of vasa RNA were detected in the cytoplasm of oocytes at all stages. In stage Ⅰ and Ⅱ oocytes, strong hybridization signals of vasa RNA were dispersed uniformly throughout the cytoplasm. With the development of oocytes and accumulation of yolk , the signals of vasa RNA significantly decreased in most of the regions while remained strong at cortical region in stage Ⅲ、 Ⅳ oocytes. During spermatogenesis, the positive signals of vasa RNA could only be detected in spermatogenia and primary spermatocytes while the signals in the former were much stronger than in the latter. However, no signals could be detected in spermatids.nanos 1 mRNA uniformly dispersed throughout the cytoplasm of oocytes at all stages. Strong expression of nanosl mRNA can be observed in oogonia and stage Ⅰ 、 Ⅱ oocytes but the signal became weaker in later stage oocytes. Strong expression of nanos 1 mRNA can be detected in spermatogonia and relatively weaker signal was found in primary spermatocytes while no expression was observed in spermatids.We speculated that : the vasa gene plays key role at early stage of goldfish spermatogenesis; in oogenesis, its products are stored in oocytes and may regulate the specification and differentiation of primordial germ cells in early embryo development. The nanosgene not only plays vital role in maintaining the self-renewal and normal function of the germline stem cell-oogonia and spermatogenia, but also is indispensable for spermatogenesis in zebrafish.更多还原