Fig. 3. shar-pei mutant cells display ectopic cell proliferation. All panels show imaginal discs stained to detect S phases by BrdU incorporation (green). (A) Wild-type and (B) eyFLP induced mosaic eye disc nearly entirely mutant for shrp¹. In wild-type, cells arrest in G1 phase in the morphogenetic furrow (arrow) and non-differentiating cells go through one synchronous S phase in the second mitotic wave (SMW, arrowhead). (B) shrp¹ mutant cells also arrest in G1 and go through a synchronous SMW, but cells then continue to proliferate posterior to the SMW (asterisk). (C,D) BrdU incorporation (green) in shrp¹ mutant clones marked by the absence of GFP (red). shrp¹ mutant cells behind the SMW (arrowhead) continue to proliferate (arrows). This effect of shrp is cell autonomous. (E) Apical and (F) basal focal plane of an eye disc with a posterior shrp¹ mutant clone stained for Elav (purple) and BrdU (green). Mutant cells were marked by the absence of GFP expression (not shown). The clone boundary is indicated by a white line in (E). BrdU-incorporating cells are located basally (F) and none of the Elav-positive cells incorporated BrdU. S phases in the SMW are marked by an arrowhead in F. Anterior is towards the left for all discs.