Fig. 4

In situ hybridization on gonads during sex-differentiation. (A-H) At 25 and 30 dpf gonads from nearly all fish exhibit expression of sox9a and cyp19a1a. (I-N) At 35 dpf dimorphic gene expression is apparent. In wild-type, dimorphic expression of sox9a is apparent (I,M) and expression is strong in all gonads from dnd-MO injected fish (J). cyp19a1a expression also becomes dimorphic in wild-type (K,N) and is no longer detectable in gonads from dnd-MO injected fish. The sox9a transcript is generally diffuse in appearance and, at 25 and 35 dpf, is primarily localized at the borders of the organ in wild-type whereas cyp19a1a transcript is localized in distinct spots presumably small somatic cells. In panels where extra-gonadal tissue is present, the gonad is denoted with black arrowheads. White arrowheads point to pigment cells.