【摘要】：正Historically,our understanding of molecular genetic aspects of germ cell development has been limited.Recently,results have demonstrated that the derivation of pluripotent stem cells may provide the necessary genetic system to study germ cell development.Here,we first characterized an induced pluripotent stem cells(iPSCs) line,which stably carried an pOct4-EGFP1 recombinant plasmid that expressed green fluorescent protein(GFP) under the control of Oct4 promoter,to confirm the pluripotent characteristic maintained.After 3 days of suspension culture,these iPSCs spontaneously differentiated into embryonic bodies(EBs),which expressed specific markers of three germ layers including AFP,Pdx1, a-actin and NSE.RT-PCR analysis confirmed that the expression of Sox2,Klf4 and C-myc were reduced when spontaneous differentiation prolonged,while Oct4,GFP and Stra8 had no remarkable difference in 3d, 5d and 8d EBs.However,the expression of Vasa,Scp3,Gdf9,Figla and Zp2 were not detected in 5d and 8d EBs.Then we induced the iPSCs to differentiate into female germ cells by culturing adherent embryoid bodies(EBs) in retinoic acid(RA) and 10%porcine follicular fluid(PFF) differentiation medium for 7 days. The extent of differentiation was evaluated through morphology and the expression of certain specific germ cell markers.Immunofluorescence analysis showed that the EBs developed into ovary-like structures and oocyte-like cells expressed germ cell markers:Vasa,meiotic specific gene-Daz1,Stra8,Scp3 and oocyte marker-Zp3.QRT-PCR analysis showed that Vasa,Stra8 and Scp3 were highly expressed in PFF-treated cells and Zp2 was highly expressed in RA-treated cells,while Oct4 was down-regulated in both of the induced cells compared to the control.These results indicate that RA and PFF are beneficial for the derivation of germ cells and oocyte-like cells from iPSCs.Finally,we transplanted iPSCs into the seminiferous tubules of an infertile mouse.The transplanted recipient testes had an increased size compared to the untransplanted testes one month after transplantation.Tissue immunohistochemistry showed the seminiferous tubules were fiberized in untransplanted testes,and cells in transplanted seminiferous tubules were positive for Vasa and Stra8,while the positive cells were not observed in huntransplanted testis.This demonstrated that iPSCs transplantation can make a contribute to repairing the testis of infertile mice.Our study offers an approach for further study on the development and the differentiation of germ cells derived from iPSCs and provides a potential therapeutic strategy for infertility and sterility.