Figure 7.

chn is required for eye morphogenesis. (A) In wild-type eye discs from early third instar larvae, Chn expression was detected at the posterior edge of the disc using anti-Chn antibody (arrows). (B, C) Adult eye morphology. (B) ey-FLP; chn¹, FRT42D/PCNA⁷⁷⁵, FRT42D. Large clones of chn¹ were formed and caused the small eye phenotype. (C) ey-FLP; tkv⁴, FRT40A/CycE^AR95, FRT40A. A large clone of tkv⁴ showed a similar eye defect. (D) In wild-type eye disc, Elav (green) was expressed behind the MF (left panel), marked with Chn (red; right panel). (E) In eye discs with large clones of chn¹, Elav-positive cells were greatly reduced in number (green; left panel, arrowheads) and were always associated with residual chn expression (red; right panel). White dots represent the border of chn¹ clone (arrows). (F) Wild-type eye disc stained with phalloidin (purple) and anti-Elav (green). (G) chn¹/chn⁹. Strong chn mutations eliminated the MF, whereas a few Elav-positive cells can be observed (arrow). (H) In eye discs with large clones of chn¹, ectopic expression of Dl was detected at the posterior edge of the disc (arrow). (I) Large clone of tkv⁴ did not induce ectopic Dl expression (arrow). Asterisks represent the position of the optic stalk where the MF propagation initiates, and arrowheads represent the position of the MF.