Ovarian ecdysteroid biosynthesis controls a mating-induced increase in GSC numbers.

<p>(A, D) Ecdysteroid levels in virgin (v) and mated (m) females in the ovarian somatic cell-specific (escort cells and follicle cells) <i>nvd</i> RNAi female flies. (A) <i>c587-GAL4</i> driver was crossed with control or <i>UAS</i> transgene strains as indicated. <i>UAS-nvd-Bm [wt]</i> and <i>UAS-nvd-Bm [H190A]</i> overexpressed the wild-type form and enzymatic inactive form of <i>Bombyx mori nvd</i> transgenes, respectively. (D) <i>nvd</i> RNAi female flies were fed food supplemented with ethanol (EtOH; for control) and 7-dehydrocholesterol (7dC). (B, E and F) Frequencies of germaria containing one, two, and three GSCs (left y axis), and average number of GSCs per germarium (right y axis) of follicle cell-specific <i>nvd</i> RNAi animals with or without the <i>B</i>. <i>mori nvd</i> transgene (B), the ovarian somatic cell-specific <i>EcR</i> RNAi female flies and transheterozygous mutants for <i>EcR</i> (<i>EcR</i>^<i>A483T</i> and <i>EcR</i>^{<i>M554fs</i>}, mutants in the predicted ligand- binding domain) (E), ovarian somatic cell-specific <i>nvd</i> and <i>sad</i> RNAi female flies that were fed food supplemented with EtOH (for control), 7dC and 20E (F). (C) Frequency of mitotic GSCs was counted by staining with anti-phospho-histone H3 in <i>nvd</i> RNAi female flies. Values are represented as the mean with standard error of the mean in A and B. The numbers of samples examined are indicated in parentheses in A and D. The numbers of germaria analyzed are shown inside bars in B, C, E and F. For statistical analysis, Dunnett’s test was used for A and D. A Mann-Whitney <i>U</i> test was used for B, E and F. Chi-square analysis was used for C. **<i>P</i> ≤ 0.01, *<i>P</i> ≤ 0.05, n.s., non-significant (<i>P</i> > 0.05).