Fig. 1. Testicular cord formation is delayed in Dax1-deficient testis. Gross examination of gonads from wild-type male (A,B) and female (E,F), and Dax1-deficient testis (C,D). Gonads were dissected from 13.5 dpc embryos; littermates were used for comparison. Testis cords are readily observed in wild-type testis, whereas a decreased number of cords, which are less organized, are present in Dax1-deficient testis (arrows) middle. Although the Dax1-deficient testis is larger than a wild-type female gonad (bottom), it is smaller than the wild-type male gonad. Coelomic and medial surfaces of gonads are displayed in left and right columns. Gonads on the right are visualized with light reflected from a mirror below the stage in order to gain better perspective for condensed tissue. Asterisks indicate the coelomic vessel.