Fig. 5. zpg is required for Dpp-induced over-proliferation of early germ cells. Flies of the indicated genotypes were either dissected (C,E), or subjected to heat shock prior to dissection (A,B,D,F), and then stained with anti-Vasa (green) and mAb 1B1 antibody (red; A,B) or anti-pMad (red; C-F). After heat shock, hs-dpp; zpg heterozygous ovaries were filled with many single germ cells (A). hs-dpp, zpg homozygous mutant ovaries did not show any proliferation of single germ cells (B). Staining of wild-type (OR) germaria revealed p-Mad staining in early germ cells (C), whereas all germ cells have nuclear p-Mad when Dpp is overexpressed (D). zpg cells also have nuclear p-Mad, whether Dpp is overexpressed (F) or not (E). Scale bar: in A, 20 µm for A,C,D; in B, 50 µm.