Figure 6.

Disrupting the Kelch–Cul3 interaction results in a failure to rescue the kelch mutant phenotype. (A–D) Confocal projections of egg chambers labeled with Kelch antibody and fluorescent phalloidin. (A and B) Egg chambers expressing Kelch^QSTN rescue the F-actin cytoskeletal defects of the kel^DE1 mutant. (A) Expression at lower levels using otuGal4 occasionally resulted in an incomplete rescue, with some accumulation of Kelch^QSTN biased toward the ring canal lumen and an F-actin phenotype intermediate between wild type and kelch-like. (B) High-level expression of Kelch^QSTN driven by matGal4 fully rescued the ring canals with respect to F-actin organization. However, matGal4-driven Kelch^QSTN formed abundant cytoplasmic aggregates and tended to form aggregates of Kelch in the ring canal lumens (high magnification ring canal images in B). (C and D) Expression of Kelch^FE at either low (C) or high (D) levels failed to rescue the kel^DE1 F-actin cytoskeletal defects (compare high-magnification ring canal images with those in Figure 3B). In addition, the Kelch^FE mutant protein accumulated in the ring canal lumen, colocalizing with the disorganized F-actin. When driven by matGal4, Kelch^FE also formed highly abundant aggregates throughout the germline cytoplasm. Scale bars, 50 µm for egg chamber images and 10 µm for cropped ring canal images.