Fig. 7. A dap null allele dominantly suppresses the two oocyte phenotype of cycE⁰¹⁶⁷² egg chambers. (A) Wild-type and (B) cycE⁰¹⁶⁷² stage 10 egg chambers stained with Dap antibody. Note that Dap accumulates to high levels in two cells, the oocyte and an adjacent cyst cell, in the cycE⁰¹⁶⁷² egg chamber. (C) In wild-type egg chambers, the posterior nurse cells have the highest DNA contents in the cyst. By contrast, in cycE⁰¹⁶⁷² egg chambers(D,E), a cell that is normally specified to become a posterior nurse cell frequently undergoes a reduced number of endocycles and has an inappropriately low DNA content (arrow). This phenotype is variable and can range from egg chambers in which the second four-ring canal cell undergoes little to no DNA replication (D) to a relatively small reduction in DNA content (E). This reduction in DNA content is suppressed by 2.5 fold when a single copy of the null allele dap⁴ is placed in the cycE⁰¹⁶⁷² background. (F) An egg chamber from a cycE⁰¹⁶⁷²,dap⁴/+ female in which the posterior nurse cells have wild-type ploidy values (compare C with F). (C-F) Egg chambers stained with DAPI to highlight nuclei.