Fig. 5

 Aberrant expression of cell cycle regulators in gnl2 and ns mutant retinae. (A–F) Transverse sections showing expression of ccnd1 at 36 hpf (A–C) and 48 hpf (D–F). In the WT retina, a subset of cells has downregulated ccnd1 (arrowheads in A), indicating their withdrawal from the cell cycle. At 48 hpf, ccnd1 is restricted to the ciliary marginal zone that remains proliferative (arrowheads in D). In contrast, ccnd1 is not downregulated in gnl2 (n = 10; B) or ns (n = 10; C) mutant retinae at 36 hpf (arrowheads) and remains expressed in the central retina of gnl2 mutants (n = 9; arrow in E). In ns mutants, ccnd1 expression is downregulated in the central retina (n = 9; arrow in F), but remains expressed in the remainder of the retina (arrowheads). (G–L) Sections showing expression of p57kip2 in the WT central retina at 36 hpf (arrow in G). In contrast, there is no expression in gnl2 (n = 11; H) and ns (n = 9; I) mutant retinae (arrows). At 48 hpf, p57kip2 expression is restricted to the lateral surface of the retina in WTs (arrowheads in J). In contrast, p57kip2 is expressed in the central retina of gnl2, (n = 12; arrow in K) and ns mutants (n = 13; arrows in L). Dashed lines indicate outline of the retina. Dorsal view, anterior to the left. le, lens. Scalebar 25 μm.