Figure 4

zipper as a genetic interactor of Drok in a screen for dominant suppressors of the DRok-cat expression-induced rough eye phenotype. (A-C) Expression of two copies of the GMR-Drok-cat transgene (GMR-Drok-cat¹, GMR-Drok-cat²) induces a rough eye phenotype associated with a smaller eye size (B) compared to a wild-type eye (A). This phenotype was dominantly suppressed by four independent EMS-induced mutations which all map to the zipper locus, the Drosophila non-muscle myosin heavy chain gene. The loss-of-function zip¹ mutation also rescued the GMR-Drok-cat¹, GMR-Drok-cat²-induced eye phenotype (C). (D-G) Tangential retinal sections of eyes of the following genotype: wild-type (D), one-copy GMR-Drok-cat transgenic (E), or one-copy GMR-Drok-cat and one mutant loss-of-function allele of either zipper (zip¹) or spaghetti squash (sqh²) (F or G, respectively). Unlike zip¹, sqh², a loss-of-function mutant of the Drosophila non-muscle myosin light chain, does not suppress the GMR-Drok-cat-induced eye phenotype. (H-J) Light microscopy photographs of a wild-type wing (H), a wing expressing en-GAL4<UAS-Drok-cat with missing crossveins (I, arrow) or a wing expressing en-GAL4<UAS-Drok-cat in a heterozygous zip¹ background (J). Heterozygosity for zipper did partially rescue the missing crossvein phenotype (J, arrow).