Spermatogonial Stem Cells

Abstract

Testicular gonocytes differentiate into spermatogonia, and spermatogonial stem cells could be established by culturing spermatogonia in vitro. Testicular and ovarian gonocytes were identified as relatively large cells in a population of gonadal cells. The proportions of testicular and ovarian gonocytes in the total gonadal cells were 0.94% and 0.75%, respectively, recognised as CVH-positive cells. The dissociated gonadal cells containing testicular or ovarian gonocytes were then transferred into recipient embryos. The presence of the donor-derived DNA was detected in the gonads of 20-day cultured recipient embryos in males and females, and also in the sperm samples obtained from the hatched male putative chimaeric chickens. In vitro culture of testicular and ovarian gonocytes was also attempted. Gonads were obtained from 19-day incubated chicken embryos and the dissociated gonadal cells were cultured in vitro. Non-adherent cells containing gonocytes were then collected and cultured further. It was confirmed that some of the testicular gonocytes proliferated in vitro. The proliferated testicular gonocytes occasionally formed cell colonies. However, no apparent proliferation was observed in the ovarian gonocytes in vitro. These results suggest that the testicular and ovarian gonocytes have the ability to enter the germline of recipient embryos, and that testicular gonocytes can be cultured and proliferated in vitro.