Fig. 3

Bursicon does not act directly on the epidermis to regulate tanning. a Abdominal cuticle of 3-h-old mosaic fly bearing patch of rk⁴/rk⁴ mutant tissue in an otherwise rk⁴/rk⁺ animal. Mutant tissue is marked by the cell-autonomous stc mutation and is outlined in red. b Quantification of pigmentation of cuticle overlying rk⁴/rk⁴ epidermal clones (red circles) or rk⁺/rk⁺ control clones (blue circles) as a function of clone size. Neither clone size nor genotype effected significantly the pigmentation at 3 h or 48 h postemergence (ANCOVA analysis; n ≥ 35 clones from 15 flies per group). c Abdominal pigmentation of flies in which tBur expression was driven in the epidermis using the TH-GAL4 and DDC-GAL4 drivers in combination with elav-GAL80 (to restrict expression to the epidermis). n = 10 for each group. Genotypes are coded as described in Fig. 1b. NS: not significantly different (one-way ANOVA, p > 0.56; n = 10 per group). d Quantification of soluble cuticular proteins extracted from wings and abdominal epidermis of flies expressing TH>tBur in combination with elav-GAL80, in rk>tBur flies, and in their respective controls. Genotypes are coded as described in Fig. 1b. Intensity of reference bands (cf. Fig. 2b) is shown for three separate experiments; median is indicated by short horizontal line. Different letters indicate statistically significant differences (one-way ANOVA followed by Tukey HSD, p < 0.001). For quantification using other bands (indicated in Additional file 1: Figure S2B), see Additional file 1: Figure S6. e Left: image of wing of engrailed>tBur (en>tBur) fly. Right: Quantification of soluble cuticular proteins extracted from the posterior and anterior half of the wing. Although the posterior half of the wing appears misfolded, the amounts of soluble protein extracted from each half did not differ significantly (measurements shown for three separate experiments; median is indicated by short horizontal line). NS: non-significant (paired t-test, p > 0.7)