Wnt6 can activate canonical wingless signaling. (A) Wnt6 can activate canonical wingless signaling when overexpressed in S2 cells. Activity of a Wnt-responsive LEF7-luciferase reporter is shown for cells co-transfected with a control plasmid or plasmids expressing Wnt6 or wingless. n = 3 Error bars: std dev. ***t-test ≤0.001 relative to control. (B) Expression levels of Wnt6 are low compared to wingless in wing discs. mRNA levels quantified by quantitative RT-PCR on w1118 wing discs. (C) Image of an anterior wing margin indicating positions of chemosensory and mechanosensory bristles. The spacing between two chemosensory bristles is on average four times the spacing between mechanosensory bristles. (D-D’) Spacing of chemosensory bristles is aberrant in adults wings of both Wnt6KO (D) and wingless hypomorphic (wg1-8/+) animals (D’). Histogram of chemosensory bristle spacing, measured using the spacing between two mechanosensory bristles as the unit length. (E-F’) Overexpression of wingless (E and F) but not Wnt6 (E’ and F’) in the patched domain with patched-GAL4 (perpendicular to the dorsal/ventral margin, arrowheads) causes upregulation of the wingless target genes, senseless (sens) and Distalless (DII). std dev, standard deviation; Wnt6KO, Wnt6 knockout.