Fig. 1

Fig. 1

The Secreted Wnt Signaling Inhibitor Dkk1b Is Produced by Androgen-Dependent Male ETs

(A) Sexually dimorphic dkk1b:EGFP expression in the heads of adult male (left) and female (right) zebrafish, present in constellations of ETs. Insets at top display enlarged version of area in white boxes. Insets at bottom indicate bright-field images. Scale bar, 1 mm.

(B) dkk1b:EGFP expression in male and female pectoral fins. Only male fins contain prominent ETs on anteromedial rays. Insets display enlarged version of area in white boxes. Note that the exterior of the anterior fin ray also expresses dkk1b:EGFP. Scale bar, 500 μm.

(C) Confocal images of longitudinal sections through dkk1b:EGFP pectoral fins, indicating male-specific ET domains (arrowheads). Both sexes display faint expression in the osteoblast compartment, although it is difficult to detect in some sections. Scale bar, 10 μm.

(D) Fluorescent (top) and bright-field (bottom) images of adult female pectoral fin rays after Eth treatment for the indicated durations. dkk1b:EGFP is detectable at 3 dpt, and ETs (arrows) are detectable at 5 dpt.

(E) Flutamide treatment decreased the number of ETs in male dkk1b:EGFP pectoral fins and reduced their definition. Insets display enlarged areas from white or black boxes. wpt, weeks posttreatment. Scale bar, 500 &mum.