Asf1b^{Gt(ROSABetageo)437Muv}

Embryonic stem cells were infected with the retroviral gene trap vector ROSABetageo, which contains a splice acceptor site joined to the Betageo (lacZ-neomycin resistance) fusion gene. The trapped gene was inactivated by integration of the vector. Tissue-specific beta-galactosidase activity has been demonstrated by X-gal staining in neural tissues of developing embryos by embryonic day 8.5 (E8.5) and in gonocytes of E15 female embryos. Expression is also observed in the male gonad by postnatal day 8; it is restricted to pachytene spermatocytes in the adult male. (J:82809)