Fig. 5. Orb and Gurken expression in K(10); orb^mel double mutant ovaries. Ovaries from wild-type (w¹), orb^mel; K(10) and K(10); orb^mel females were simultaneously stained with antibodies against Orb (red) and Grk (green). To make protein levels comparable between the different ovaries, the ovaries were stained in parallel and analyzed by confocal microscopy using identical conditions. Background staining by the Grk antibody is nonspecific and present in the same pattern in grk-null egg chambers (data not shown). The genotypes are as indicated in each panel. In the wild-type stage 10 egg chamber (top left panel) Grk protein is localized to the anterior corner of the oocyte above the nucleus, while Orb protein can be seen as a ring around the edges of the oocyte. In the orb^mel stage 10 egg chamber (top middle), neither Grk nor Orb is observed. In the K(10) stage 8-9 egg chambers (top right), the level and localization of Orb resembles that seen in wild type, while Grk protein can be seen along the anterior margin of the oocyte (as yellow staining). In the K(10); orb^mel egg chambers shown in the panels at the bottom, the level of Orb protein is greatly increased compared with that seen in the orb^mel chamber, and the localization pattern appears to be quite similar to that seen in wild-type egg chambers. Note that red staining can be seen around the circumference of each of the double mutant oocytes. As in K(10) mutant chambers, Grk protein can be seen along the entire anterior margin of the double mutant oocytes.