Fig. 5

Expression of wnt4a during reproductive duct development in zebrafish wild-type AB strain males. Alternate serial cross sections of wild-type males were stained by H&E to follow duct growth (see Figure S6) or prepared for in situ hybridization to reveal wnt4a expression, shown here. (A) Expression analysis showed that at 25 dpf, the duct deferens (cross section of the right duct shown here) lacked wnt4a expression. (B) At 25 dpf, however, wnt4a expression (→’s) appeared dorsal to the posterior vent, just anterior to the eventual connection of the fused duct deferens and the genital orifice. (C) At 35 dpf, the duct deferens continued to show little wnt4a expression. Insert shows the left and right duct deferens dorsal to the intestine. (D) At 35 dpf, wnt4a expression (→’s) appeared dorsal and lateral to the posterior vent, just anterior to the eventual connection of the fused ducti deferens and the genital orifice. (E) At 55 dpf, in a section just anterior to the fusion of the duct deferens to the vent, wnt4a expression (→) appeared dorsal to the posterior vent, just anterior to the connection of the fused ducti deferens and genital orifice. (F) At 55 dpf, in a section at the level of the connection of the fused duct and the vent, wnt4a expression (→) appeared just dorsal to the genital orifice. DD, ducti deferens; FDD, fused ducti deferens; GO, genital orifice; I, intestine; LDD, left duct deferens; PD, pronephric duct; RDD, right duct deferens; V, vent. Bar, 100 µm.