Ovaries lacking germ cells do not transdifferentiate towards a Sertoli cell fate.

<p>(A–C) SOX9 (red) and FOXL2 (green) immunostaining of cryosectioned 17.5 dpc gonads. (A) XY <i>Kit^+/+</i> testes express SOX9, but not FOXL2 (XY germ cells exhibit high background staining). (B–C) XX <i>Kit^+/+</i> and <i>Kit^Wv/Wv</i> ovaries express only FOXL2 and show no evidence of transdifferentiation. (D–F) AMH (red) and SCP3 (green) immunostaining of the same samples as in A–C. (D) As expected, XY <i>Kit^+/+</i> testes express AMH, but not the meiotic germ cell marker SCP3. (E–F) XX <i>Kit^+/+</i> and <i>Kit^Wv/Wv</i> ovaries do not express AMH. SCP3 immunostaining confirms significant germ cell loss in <i>Kit^Wv/Wv</i> ovaries (E,F). All samples were cryosectioned then immunostained. The scale bar represents 50 µm in all panels. The dotted line demarcates the boundary of the ovary.