Although sex determination in birds, as in mammals, is chromosomally based, its mechanism has been a long-standing mystery. In birds, the homogametic sex is male (ZZ) and the heterogametic sex is female (ZW); one hypothesis is that two doses of a Z-linked gene are required for male development. Here it is shown that reducing expression of the conserved Z-linked gene DMRT1 feminizes the embryonic gonads in genetically male (ZZ) chicken embryos.
- Craig A. Smith
- Kelly N. Roeszler
- Andrew H. Sinclair
