Fig. 1: Loss-of-function mutations in Fbxo42 suppress glossy eye phenotype caused by overexpression of Xbp1spliced.
From: Fbxo42 promotes the degradation of Ataxin-2 granules to trigger terminal Xbp1 signaling
a Wild-type adult Drosophila eye (Canton S). Posterior is to the right and dorsal to the top in this and all subsequent panels. Scale bar = 200 μm. b Glossy eye phenotype caused by overexpression of Xbp1spliced (Xbp1s). Genotype: GMR-GAL4, UAS-Xbp1s, UAS-DsRed. c Glossy eye phenotype is suppressed by co-expression of Xbp1unspliced (Xbp1u). Genotype: GMR-GAL4, UAS-Xbp1s, UAS-Xbp1u. d Glossy eye phenotype is suppressed by co-expression of caspase inhibitor P35. Genotype: GMR-GAL4, UAS-Xbp1s, UAS-P35. e Glossy eye phenotype is suppressed by co-expression of DIAP1. Genotype: GMR-GAL4, UAS-Xbp1s, UAS-DIAP1. f Genetic scheme of the FLP/FRT F1 genetic screen for suppressors of the glossy eye phenotype caused by overexpression of Xbp1s. g Glossy eye phenotype is suppressed by clones of suppressor 209. Genotype: eyFlp,GMR-GAL4,UAS-Xbp1s; FRT42D, Su209/FRT42D, ubiGFP. h Glossy eye phenotype is suppressed by clones of suppressor 218. Genotype: eyFlp,GMR-GAL4,UAS-Xbp1s; FRT42D, Su218/FRT42D, ubiGFP. i Schematic representation of Fbxo42 (amino acids 1–667), with the F-box domain (blue box) and the mutations found in six of the suppressor alleles (Su209, Su212, Su217, Su218, Su226 and Su359) obtained from the genetic screen. Su212, Su217 and Su218 have a small deletion that causes a frameshift and premature Stop codon at 423. j Overexpression of Fbxo42-GFP abolishes suppression of glossy eye by Su209. Genotype: eyFLP,GMR-GAL4,UAS-Xbp1s; FRT42D, Su209/FRT42D, ubiGFP; UAS-Fbxo42-GFP. k A genomic rescue construct containing Fbxo42 (Pacman CH322-12H15) abolishes suppression of glossy eye by Su359. Genotype: eyFLP,GMR-GAL4,UAS-Xbp1s; FRT42D, Su359/FRT42D, ubiGFP; CH322-12H15. l Immunofluorescence of 3rd instar larva eye discs containing clones of Su218, labeled by the absence of ubiGFP (green). GMR-GAL4 driven expression of UAS-DsRed is similar in Su218 and ubiGFP clones. Genotype: eyFlp,GMR-GAL4, UAS-DsRed; FRT42D, Su218/FRT42D, ubiGFP. Three independent replicates were conducted. Scale bar = 30 μm. m Glossy eye phenotype caused by overexpression of Rh1. Genotype: eyFlp,GMR-GAL4; FRT42D/FRT42D, GMR-hid, CL;UAS-Rh1. n Whole eye mutant clones of Su218 suppress glossy eye phenotype caused by overexpression of Rh1. Genotype: eyFlp,GMR-GAL4; FRT42D, Su218/FRT42D, GMR-hid, CL;UAS-Rh1. o Small eye phenotype caused by overexpression of hid. Genotype: eyFlp,GMR-hid; FRT42D/FRT42D,ubiGFP. p Clones of Su218 do not suppress the small eye phenotype caused by overexpression of hid. Genotype: eyFlp,GMR-hid; FRT42D, Su218/FRT42D,ubiGFP. q Immunofluorescence of 3rd instar larva eye discs containing clones of Su218, labeled by the absence of ubiGFP (green), with an antibody made against Fbxo42 (Red). DAPI is in blue. Genotype: eyFlp,GMR-GAL4; FRT42D, Su218/FRT42D, ubiGFP. Scale bar = 60 μm. Three independent replicates were conducted.
