Fig. 4. Ectopic co-expression of wg and vg transforms the PE into wing blade. (A) wg-vg expressing clones (green, 24-48 hours AEL) transform squamous cells into columnar wing blade cells (see longitudinal section s1 through the outlined clone). Vg (blue) is present only in cells of the clone, while nub (red) is expressed both cell autonomously and non-autonomously. (B) wg-vg expressing clones generated 24-48 hours AEL induce the expression of the hinge marker zfh-2 in an exclusively non-autonomous way (see transverse section s2). The arrowheads indicate a clone in the wing-notum side that neither induces zfh-2 expression in apposed peripodial cells nor affects their morphology. Note that the clone in the peripodial side does not induce zfh-2 expression in the wing-notum side either. Arrows indicate untransformed peripodial nuclei. (C) Clones generated 48-72 hours AEL promote autonomous expression of the wing pouch genetic marker dll. In contrast to earlier clones, the induced expression of nub is exclusively non-autonomous (insets at higher magnification).