Oct-4 expression in testicular germ cells

The Octamer-binding transcription factor 4 (Oct-4) is a mammalian key transcription factor expressed by embryonic stem cells and primordial germ cells and is involved in the regulation and maintenance of pluripotency and cell survival. To enhance our understanding of the Oct-4 expression levels and -function in testicular germ cells, as an in vitro model for spermatogonial stem cells, we used Fluidigm RT-PCR and immunohistochemical analysis of Oct-4 in the mouse testis section and testicular culture. The immunocytochemical staining displayed that Oct-4 protein was exclusively expressed in the seminiferous tubules of the testis. Germ stem cell (GSCs) colonies were established after the digestion of testis. The immunohistochemical analysis confirmed that Oct-4 protein was localized in the nucleoplasm of GSCs. The Fluidigm RT-PCR results revealed a high expression of the germ cell gene Oct-4 in GSCs and mouse embryonic stem cells (mESCs), and a low expression in testicular stroma cells (TSCs) feeders. The Oct-4 gene is necessary for GSC maintenance in an undifferentiated state and for self-renewal and could be useful as a source of embryonic stem-like cells.