Expression of <i>aldh1a2</i> and <i>cyp26a1</i> is independent of germ cell signaling.

<p>Animals depleted of germ cells that develop into sterile males were generated by <i>dead end</i> (dnd) morpholino knockdown to study the expression of <i>aldh1a2</i> and <i>cyp26a1</i> in gonads at (A-C: n=1) bipotential stage (19dpf), (D–F: n=1) transitioning stage (25dpf), and (G-I: n=1) differentiated testes (37dpf). Results showed that <i>aldh1a2</i> was widely expressed in somatic cells of the gonads at the three different stages analyzed (A,D,G) while <i>cyp26a1</i> expression was detected in a subset of somatic cells also in the three stages analyzed (arrows in B, E, H). These results demonstrate that the onset as well as the maintenance of <i>aldh1a2</i> and <i>cyp26a1</i> expression, at least until 37dpf, is independent of germ cell signaling. Expression of the germ cell specific marker <i>vasa</i> was not detected at any stage (C,F,I), confirming the total depletion of germ cells by <i>dnd</i> morpholino injection in all animals. Gonads are outlined by a dashed line (B,C, E, F,H,I). Scale bar: 0.05 mm (A).