Conditional ablation of Gata4 and Fog2 genes in mice reveals their distinct roles in mammalian sexual differentiation

► Gata4 is required for testis differentiation and for the expression of Dmrt1 gene. ► Gonadal loss of Fog2 results in a partial block in the male pathway and sex reversal. ► Testis sexual differentiation is sensitive to the timing of GATA4 loss. ► Gata4 and Fog2 genes have non-overlapping essential functions in testis development.