Fig. 1. Yki is predominantly cytoplasmic. Panels show regions of wing imaginal discs; in this and subsequent figures, panels marked ' show separate channels of the stain on the left. (A,A') yki^B5 mutant clones (black arrows), marked by absence of lacZ (magenta), with UAS-yki:GFP (green) expressed under ci-Gal4 control. Twin clones (white arrows) are visible in both anterior and posterior compartments. (B,B') Yki:GFP (green) expression in posterior cells (right) under en-Gal4 control; nuclei are marked by DAPI stain (blue). Nuclear Yki:GFP is barely above background. (C,C') Yki-S168A:GFP (green) expression in posterior cells (right) under en-Gal4 control. Levels of nuclear Yki-S168A:GFP are higher than for Yki:GFP, but it is still predominantly cytoplasmic. (D,D') yki^B5 mutant clones, marked by absence of lacZ (green), and stained for DNA (DAPI, blue) and Yki (red). (E,E') Vertical section through the disc shown in D. The center of the wing disc forms a pseudostratified epithelium, with nuclei in different focal planes. Yki staining is detected throughout the apicobasal aspect of these cells, but is low in nuclei (e.g. as highlighted by asterisks to the right of nuclei).