Sgg and Hyd genetically interact to govern animal viability and head and wing development.

<p>(A-J) Sgg perturbation modifies the <i>hyd</i>^{<i>k7</i>.<i>19</i>} head phenotype. (A-D) Brightfield images of adult <i>Drosophila</i> heads of the indicated genotypes shown either ‘head on’ (upper panels) or ‘side on’ (lower panels). Both gain (C) and loss (D) of <i>sgg</i> function appeared to rescue the <i>hyd</i>^{<i>k7</i>.<i>19</i>} phenotype. Boxplots indicating head width (E, n = ≥8 for each genotype) and counts of eye scars (F, n = ≥8 for each genotype) of the indicated genotypes, with statistical analysis by one-way ANOVA (E) and Fishers exact test (F) revealed statistical significance (asterisks). (G-J) Representative GFP fluorescent signals in adult <i>Drosophila</i> heads of the indicated genotypes revealed only <i>hyd</i>^{<i>k7</i>.<i>19</i>}<i>+sgg</i>^<i>S9A</i> animals lack a GFP signal (n = ≥4 for each genotype). Scale bars = 175μm. (K-P) <i>hyd</i>^<i>WT</i> overexpression promotes the <i>sgg</i>^<i>S9A</i>-mediated wing phenotype. (K-N) Brightfield images of adult <i>Drosophila</i> wings showing (K) normal, (L) mildly deformed, (M) severely deformed and (N) wing-to-notum phenotypes. (O) Percentage of adult wing phenotypes of <i>vg-GAL4</i> flies expressing the indicated transgenes, revealing that the <i>hyd</i>^<i>WT</i> transgene enhanced, and the <i>hyd</i>^<i>C>A</i> transgene suppressed the severity of the <i>sgg</i>^<i>S9A</i> wing defects (n ≥12 for each genotype). (P) Model showing the genetic interaction between <i>sgg</i>^<i>S9A</i> and <i>hyd</i> UAS-transgenes with respect to the wing-to-notum phenotype. Arrows indicate promotion and blockhead arrows inhibition. (Q-R) <i>hyd</i>^<i>WT</i> overexpression rescues <i>sgg</i>^<i>RNAi</i>-mediated embryonic lethality. Percentage viability of <i>sca-GAL4</i> flies expressing the indicated transgenes revealed a >95% rescue of embryonic lethality upon co-expression with the <i>UAS-hyd</i>^<i>WT</i>, but not <i>UAS</i>-<i>hyd</i>^<i>C>A</i>, transgene (16 individual crosses per genotype). (R) Model showing the genetic interaction between <i>sgg</i> and <i>hyd</i> UAS-transgenes. Arrows indicate promotion, blockhead arrows inhibition and dotted blockhead arrow weak inhibition. Scale bar = 250μm.