Figure 3.

Kelch protein resistant to autocatalytic degradation is fully functional. (A and B) Confocal maximum intensity projections of egg chambers labeled with Kelch antibody and fluorescent phalloidin. (A) Wild-type stage 10 egg chamber. Inset shows higher-resolution image of a ring canal, revealing the F-actin cytoskeleton and associated Kelch protein. (B) Stage 10 egg chamber from a kel^DE1 female. The oocyte is considerably smaller than the comparably staged wild-type egg chamber in A, ring canals lack detectable Kelch protein, and the F-actin cytoskeleton largely occludes the lumens of the ring canals. (C and D) Ovaries from kel^DE1 rescued with a wild-type cDNA driven at low (otuGal4, C) or high (matGal4, D) levels of expression. kel^DE1 egg chambers rescued with otuGal4 resemble wild-type egg chambers. Ovaries rescued with high-level Kelch expression using matGal4 accumulate cytoplasmic aggregates of Kelch (D), but Kelch localizes to ring canals and rescues the cytoskeletal defects. (E and F) Kelch^K0 rescues the kelch ring canal cytoskeletal phenotype at both low (E, otuGal4) and high (F, matGal4) levels of expression. Accumulation of Kelch cytoplasmic aggregates was greatly enhanced with matGal4-mediated expression (F). Scale bars, 50 µm for egg chamber images and 10 µm for cropped ring canal images.