Fig. 1. Geminin levels are low during endocycles. Wild-type (A,A') ovariole, (B,B') stage 13 Drosophila embryo and (C,C') larval salivary glands stained with (A,B,C, white; A',B',C' inset, green) -Geminin and (A', inset, red) --Spectrin antibodies, and (A',B',C' inset, blue; C', white) DAPI. (A,A') Geminin is expressed in mitotic follicle cells of the ovary (stage 1-6), but is absent from endocycling cells after stage 6 (arrow), with the exception of the polar cells (asterisk). Geminin levels are downregulated when germline nurse cells enter into the endocycle in region 3 of the germarium (localized by the -Spectrin antibody staining; A', inset). (B,B') During embryogenesis, Geminin expression is shown in mitotic cells, but is absent from endocycling cells. (C,C') Geminin staining is also absent in the larval salivary gland, except for the imaginal ring of the salivary gland (insert, arrow), which contains diploid adult precursor cells. mr¹/mr² mutant (D,D') ovariole and (E,E') larval salivary gland, labeled with (D,E, white; D',E', insets, green) -Geminin antibody and (D',E', white; D',E', insets, blue) DAPI. Geminin is ectopically expressed in mr mutant nurse cells and in salivary glands cells.