Fig. 7. Temporal and spatial regulation of tsh repression by Pc. (A) Time line of clone induction. Red bars indicate windows in which Pc^- clones were induced by heat shock relative to hours after egg laying (AEL) and tsh repression. Note that the 72-84 and 84-96 hours AEL time points occur after the initiation of tsh repression in the second instar. (B-M) tsh expression (red) in Pc^– clones, marked by the absence of GFP. (B,C) Pc^– clones induced 84-96 hours AEL express tsh in the most distal cells of the hinge (white arrow), but not in the wing pouch. (D,E) Pc^– clones induced 72-84 hours AEL express tsh in the wing pouch and distal hinge (white box, enlarged). (F,G) tsh expression levels in Pc^– clones induced 48-60 hours AEL are comparable to endogenous hinge and notum levels. (H,I) Large Pc^– clones induced 24-36 hours AEL. Although tsh is widely expressed in the mutant tissue, it is not expressed in cells close to the DV boundary (white box, enlarged) or PH (yellow arrowhead). (J-M) Pc^– MARCM clones, marked by GFP, induced in early second instar larvae. (J,K) Control Pc^– clones de-repress tsh. (L,M) Pc^– clones expressing Nrt-Wg do not de-repress tsh.