Figure 8.

Overexpression phenotypes in leg and wing blade. Overexpression of sple in da–UAS:sple⁺ [EP(2)2557/+; gal4–da/+] legs gives no mutant phenotype; the wild-type morphology of T3 and T4 tarsal segments is shown in A. For comparison, the duplicated proximal (ball) and distal (socket) joint structures of the T3 and T4 segments resulting from lack of function in pk^pk–sple-3 legs is shown in B; the T1, T2, and T5 segments (not shown) remain normal. A more extreme tarsal duplication phenotype affecting T1–T4 segments is given by Pk overexpression in 765–UAS:pk⁺ (P[UAS:pk]⁺/gal4–C765) flies (C). (D,E) The same region anterior to vein 4 in two different da–UAS:sple [EP(2)2557/+; gal4–da/+] wings. The polarity in any given region is unpredictable from wing to wing, but hair orientation changes gradually across large fields of cells. Whorls, cruciform, and radial stacking flaws are seen as in pk^pk wings, but at variable positions within the wing blade.