研究证实，脊椎动物成体卵巢中依然存在雌性生殖干细胞（germline stem cells,GSC），开启了雌性GSC研究新纪元。我们在3月龄罗非鱼已分化卵巢中观察到雌性GSC样细胞,同时成功诱导其性逆转为功能性精巢。我们推测，已分化卵巢存在雌性GSC且能转分化为雄性GSC。本研究拟通过细胞增殖能力检测、细胞培养及细胞移植鉴定罗非鱼成体卵巢中雌性GSC；RT-PCR、qPCR、原位杂交、免疫组化等分离、鉴定雌、雄性GSC相关分子标记；细胞移植检测雌性GSC转分化形成功能性精子的能力，细胞增殖能力检测、原位杂交、免疫组化等检测人工诱导已分化卵巢性逆转模型中雌性GSC的迁移及相关分子标记的表达变化，及性逆转精巢组织中雄性GSC的发生、增殖、分化与相关分子标记的表达变化，探索雌性GSC转分化及其机制。该研究将推进雌性GSC及其分化调控机制的深入研究，同时为揭示已分化卵巢性逆转机制奠定基础。

The latest studies have revealed that germline stem cells (GSC) are present in adult vertebrate ovaries, which brought us into an epoch of female GSC. In our prophase research, germline stem-like cells were observed in the differentiated ovaries of three-month-old Nile tilapia (Oreochromis niloticus）,which could be successfully reversed to functional testes by aromatase inhibitor (Fadrozole) treatment. These data strongly suggest that female GSC might be present in the differentiated ovaries of Nile tilapia and possess the potential of transdifferentiation into male GSC. To identify female GSC in differentiated ovaries of Nile tilapia, mitotically active germline cells will be firstly examined by histological observation and BrdU incorporation method; then in vitro culture system of female GSC will be established and labeled with biological dye PKH26, which will be transplanted into female red tilapia sterilized by pre-treatment with busulphan to destroy the existing germ cell pools. Through transcriptome analysis from Nile tilapia gonads, related molecular markers for female and male GSC of Nile tilapia will be isolated by RT-PCR and 5', 3'-RACE, and then be characterized by qPCR, in situ hybridization and immunohistochemistry. As the above mentioned way, PKH26 labeled female GSC will be transplanted into male red tilapia to investigate the potential of female GSC of transdifferentiation into functional sperms. Based on a model in which differentiated ovary has been artificially induced to reverse to functional testis, migration and expression profiles of related molecular makers of female GSC will be investigated through BrdU incorporation method, in situ hybridization and immunohistochemistry; meanwhile, germination, proliferation, differentiation and expression profiles of related molecular markers of male GSC in the sex-reversed testis will also be investigated. Taken together, the potential and molecular mechanisms of female GSC of transdifferentiation will be elucidated. This work will promote the study of regulation mechanisms of differentiation of female GSC, and provide insight into molecular mechanisms of sex reversal of differentiated ovary.