Figure 4.

DNA damage occurs before SC formation in dap^−/− ovarian cysts. Wild-type (A) and dap^−/− mutant germaria (B) labeled with α-γ-H2Av (A, B, red) and α-C(3)G (A′, B′, green) antibodies and DAPI (A–B′, blue). The magnified images in the middle (a₁–b₂) show C(3)G protein (green) and γ-H2Av foci (red) (a₁ and b₁) in one cell of a 16-cell cyst in early region 2a before the appearance of α-C(3)G staining and in one of the two pro-oocytes in region 2a after the appearance of α-C(3)G staining (a₂ and b₂). Note that whereas no α-γ-H2Av staining is seen in a₁, wild-type 16-cell cysts of region 2a before the appearance of C(3)G, (b₁) dap^−/− mutant cells of the same region show several γ-H2Av foci. In meiotic region 2a, when C(3)G protein is expressed, an increased number of γ-H2Av foci are observed in dap^−/− mutant pro-oocytes (b₂) compared with wild type (a₂).