Analyse Of The Expression Of Zebrafish Nanosl Gene And Goldfish Vasa Gene During Gametogenesis By In Situ Hybridization

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 â…  and â…¡ 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 â…¢, â…£ 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 â…  , â…¡ 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.