Figure 3. ar-null male zebrafish have female secondary sex characteristics.

(A-C) Wildtype (ar^+/+) and heterozygous (ar^+/-) male adult zebrafish have deep yellow pigmentation of the anal fin and breeding tubercles (BT) in the pectoral fin (red arrows); ar-null male zebrafish (ar ^-/-; ar ^{ihb1225/ihb1225}) had light yellow pigmentation of the anal fin and no pectoral BTs; ar-null male zebrafish (ar^-/-; ar ^{ihb1225/ihb1225}) also had a female-like appearance and a larger abdomen. Mpf, month post fertilization.