Figure 7

D- type Cyclins are aberrantly expressed in Sox2- ablated optic cup progenitor cells (OCPCs) at E16.5. Expression of D-Cyclins and Shh was assayed on transverse sections through E16.5 eyes. (A-F) CyclinD1 protein is increased in GFP-positive/Sox2-ablated cells (C-F arrowheads) compared with controls (A, B). High power magnification of the boxed area in (E) shows cell-autonomous up-regulation of CyclinD1 (C, F). CyclinD1 protein is also elevated in the peripheral NR of controls (arrowheads in A, B). (G- H, J- K) CyclinD3 is restricted to the peripheral OC/prospective ciliary epithelium (CE) of controls (G, H, arrowhead) and is ectopically expressed in central mutant OCPCs (box in K), supporting NR-to-CE cell fate conversion. Note that speckled staining in the inner region of the optic cup visible in (H, K, O, P) is non-specific background. (I, L) Shh mRNA expression is decreased in central OCPCs of mutants (L) compared with controls (I). (M-P) High power magnification of the boxed area in (K) shows that CyclinD1 and CyclinD3 are aberrantly co-expressed in some Sox2-mutant central OCPCs (arrows in P). Black arrowheads in (I) and (L) indicate the extent of Shh expression. The boxed regions in (I) and (L) are magnified twice in the inserts in each panel. Scale bars: 50 μm.