Figure 7.

Screening for genetic modifiers of the eye pigmentation phenotypes of fly mutants deficient in BLOC-1 subunit 1 (blos1^ex2) or in AP-3 subunit σ3 (or^49h). (A and B) Quantification of red pigments extracted from the heads of male flies homozygous for the mutant alleles blos1^ex2 (A) and or^49h (B) and carrying P-element insertions for GAL4-dependent misexpression of the products of the indicated candidate genes. Two independent P-element insertions nearby Rab11, labeled as ‘1’ and ‘2’, were used. Controls included Canton-S (CS) flies and homozygous mutant flies devoid of P-elements for GAL4-dependent misexpression (–) and either lacking (open bars) or carrying (filled bars) the GMR-GAL4 driver. Values are expressed as percentages of the pigment content of Canton-S flies and represent means ± SD. (C) Additional analyses were performed as in (A) and (B) to test whether the effects observed for the constructs targeting auxilin and Rab11 (P-element insertion 1) were dependent on the presence of the GMR-GAL4 driver. One-way ANOVA followed by Bonferroni comparison of selected group pairs: NS, not significant; **P < 0.01; ***P < 0.001. (D) Eye color phenotypes of g² mutant male flies carrying the UAS-aux transgene for misexpression of Auxilin, the GRM-GAL4 driver, or both. See Supplementary Materials, Table S1 for the corresponding quantitative analysis.