Figure 8.

Figure 8.

Müller glia in the mdka^mi5001 mutant arrest in the G₁ phase of the cell cycle. A–C, qPCR assay for cell cycle regulator cyclins, ccnd1, ccne1, and ccna2 following photolytic lesion. Both WT and mdka^mi5001 upregulate G₁ cyclins, ccnd1 (A; WT: 30 hpl, p = 0.0107, 36 hpl, p = 0.0013; mdka^mi5001: 30 hpl, p = 0.0048, 36 hpl, p = 0.0213; F-ratio = 12.0576) and ccne1 (B; WT: 30 hpl, p < 0.0001, 36 hpl, p < 0.0001; mdka^mi5001: 30 hpl, p = 0.0012, 36 hpl, p = 0.0001; F-ratio = 36.5808), following lesion (A,B). The mdka^mi5001 mutant fails to upregulate S phase cyclin, ccna2 (C; WT: 36 hpl, p = 0.0011; F- ratio = 12.5433). D, S phase assay with BrdU labeling (green) between 24 and 30 hpl. Müller glia in the mdka^mi5001 mutants did not incorporate BrdU following lesion. E–H, qPCR of additional cell cycle regulators. Expression of cyclin-dependent kinases, cdk4 (E; WT: 36 hpl, p < 0.0001; F-ratio = 15.8783) and cdk6 (F; WT: 36 hpl, p = 0.0087; F- ratio = 8.3300), is dysregulated in the mdka^mi5001 retinas (E,F). The WT transiently upregulates id2a at 30 hpl (p = 0.0003; F- ratio = 7.2578), whereas expression levels did not change in the mdka^mi5001 (G). Expression of the cell cycle inhibitor, p130, decreases in the WT after lesion, whereas mdka^mi5001 maintains steady levels of expression (H; p = 0.002, relative to WT; F- ratio = 6.3823). ANOVA with post hoc Tukey, relative to unlesioned. Scale bar: D, 30 μm. onl, Outer nuclear layer; inl, inner nuclear layer; gcl, ganglion cell layer. *p < 0.03, ^#p < 0.01.