Fig. 5. The function of -endosulfine might be evolutionarily conserved. (A-D) DAPI-stained stage 14 oocytes from control and endos⁰⁰⁰⁰³ females expressing Endos or human -endosulfine (ENSA). (A) Control oocytes arrested in metaphase I. (B) endos mutant oocytes with dispersed DNA. (C,D) nanos-Gal4::VP16-driven germline expression of UAS-endos (C) or UAS-ENSA (D) transgenes showing endos rescue. Arrows indicate fourth chromosomes. Scale bar: 5 µm. (E) Western analysis showing ovarian expression of Endos and ENSA in rescued females. Actin was used as a loading control. Arrowheads indicate ENSA-specific bands (lower bands are probably degradation products), which are absent in the `No rescue' control. (F) Quantification of endos⁰⁰⁰⁰³ rescue. The number of stage 14 oocytes (metaphase I arrest and dehydration) or eggs (hatch rate) analyzed is shown above the bars. ^*P<0.001. (G,H) Mouse ovary immunohistochemistry showing that anti-Endos antibodies strongly label the cytoplasm of oocytes (H), whereas no signal is detected by pre-immune serum (G). o, oocyte (arrows); c, cumulus cells; g, granulosa cells; a, antrum; i, interstitial cells. Scale bar: 200 µm.