Most follicular epithelia are normal when the M region is deleted. (A) Follicular epithelium clones positively marked with GFP in indicated genotypes. α-Cat null mutant cells show strongly reduced levels of Arm and display cytoplasmic aggregates of α-Spectrin. Expression of α-CatR and α-Cat-ΔM in α-Cat mutant cells substantially rescue these defects. Scale bar, 20 μm. (B) Comparison of rescue activities of α-CatR and α-Cat-ΔM when expressed in α-Cat mutant cells in the follicular epithelium. Data are presented as mean ± SEM, n = number of cells analyzed, pooled from a number of clones.