Fig. 2. Orb staining in wild-type and mio ovaries. Wild-type (A,C) and mio mutant (B,D) germaria stained with Orb (green) and Hoechst (blue). (A) In wild type, weak Orb accumulation is first observed in a single cell in region 2a (arrow), and becomes strong by region 2b. (B) In mio mutants, Orb accumulation in a single cell is not visible until late region 2b (arrow) or sometime until region 3. (C) In wild type, Orb continues to accumulate at the posterior cortex of the oocyte during post-germarial stages (arrowheads). (D) In mio mutant egg chambers, some Orb proteins do not move to the posterior in stage 2 (see B), remain detectable in the anterior of the oocyte, and gradually disappear when the oocyte enters the endocycle.