The Drosophila FUS ortholog cabeza promotes adult founder myoblast selection by Xrp1-dependent regulation of FGF signaling
Fig 3
Reduced founder myoblast number in caz mutants and rescue of caz mutant muscle phenotypes by adult myoblast-selective caz expression.
A, Immunostaining of duf-lacZ/Y transgenic pupal filets 24 h APF for β-galactosidase and Caz revealed Caz expression in founder myoblasts. Scale bar: 10μm. B, Immunostaining of founder myoblasts in a dorsal abdominal segment (A3 or A4) of 24 h APF duf-lacZ pupal filets, either WT (duf-lacZ/Y) or cazKO (cazKO,duf-lacZ/Y), for β-galactosidase (green) and Futsch (red). Scale bar: 20μm C, Quantification of the number of founder myoblasts in a dorsal abdominal segment (A3 or A4) of WT (duf-lacZ/Y) and cazKO (cazKO,duf-lacZ/Y) pupae at 24 h APF. Unpaired t-test; ***p<0.001; n = 8 WT versus 15 cazKO. Average ± SEM. D, Quantification of the number of founder myoblasts in a dorsal abdominal segment (A3 or A4) of 24 h APF cazKO pupae in which caz is selectively expressed in adult myoblasts (cazKO,duf-lacZ,1151-GAL4/Y;; UAS-caz/+) as compared to the relevant control genotypes (duf-lacZ,1151-GAL4/Y // duf-lacZ,1151-GAL4/Y;; UAS-caz/+ // cazKO,duf-lacZ,1151-GAL4/Y). Two-way ANOVA with Tukey’s multiple comparisons test; **p<0.001, ***p<0.001; n = 13 per genotype. Average ± SEM. E,F, Quantification of DAM number (E) and percentage of misoriented DAMs per animal (F) in segment A4 of 96 h APF cazKO pupae in which caz is selectively expressed in adult myoblasts (cazKO,1151-GAL4/Y; Mhc-GFP,his-RFP/+; UAS-caz/+) as compared to the relevant control genotypes (1151-GAL4/Y; Mhc-GFP,his-RFP/+ // 1151-GAL4/Y; Mhc-GFP,his-RFP/+; UAS-caz/+ // cazKO,1151-GAL4/Y; Mhc-GFP,his-RFP/+). Statistics (E): Brown-Forsythe and Welch ANOVA with Dunnett’s post test; **p<0.01, ***p<0.001; n = 8 per genotype. Average ± SEM. Statistics (F): One sample Wilcoxon signed rank test to compare all genotypes to control (set to 0), t-test with Welch’s correction to compare cazKO to cazKO;; UAS-caz/+; *p<0.05, **p<0.005, ***p<0.0001; n = 9 control, 8 UAS-caz, 10 cazKO, 18 cazKO; UAS-caz. G, Quantification of the number of founder myoblasts in a dorsal abdominal segment (A3 or A4) of 24 h APF pupae in which caz is selectively inactivated in myoblasts (cazFRT,duf-lacZ,1151-GAL4/Y; UAS-FLP/+) as compared to the relevant control genotype (cazFRT,duf-lacZ,1151-GAL4/Y). Unpaired t-test; ***p<0.0001; n = 18 cazFRT, 25 cazFRT; UAS-FLP. Average ± SEM. H,I, Quantification of DAM number (H) and percentage of misoriented DAMs per animal (I) in segment A4 of 96 h APF pupae in which caz is selectively inactivated in myoblasts (cazFRT,1151-GAL4/Y; Mhc-GFP,his-RFP/UAS-FLP) as compared to the relevant control genotype (cazFRT,1151-GAL4/Y; Mhc-GFP,his-RFP/+). Statistics (H): Mann Whitney test; ***p<0.0001; n = 23 cazFRT, 22 cazFRT; UAS-FLP. Average ± SEM. Statistics (I): One sample Wilcoxon test; *p<0.05; n = 23 cazFRT, 22 cazFRT; UAS-FLP. Average ± SEM.