Figure 2

The retina of cct5^{𝑡𝑓121𝑏}mutants is smaller and characterised by enhanced proliferation and apoptosis. (A) Quantification of the retina sizes revealed that the retinal area of cct5^{𝑡𝑓121𝑏} homozygotes was significantly smaller compared to siblings. The mean retinal area of cct5^{𝑡𝑓121𝑏} homozygotes was 17.8 ± 0.8 (×10³ μm²) at three dpf and 23.8 ± 0.2 (×10³ μm²) at six dpf compared to siblings that featured mean retinal areas of 24.7 ± 0.5 (×10³ μm²) at three dpf and 28.4 ± 0.5 (×10³ μm²) at six dpf; n = 10 per genotype and stage. (B) In contrast to three-dpf-old siblings, more BrdU-positive cells (green) were detected at the periphery of the retina within the ciliary marginal zone of cct5^{𝑡𝑓121𝑏} homozygotes. (C) Quantification of the number of BrdU-positive cells within individual retinas revealed that significantly more cells were proliferating within the ciliary marginal zone of cct5^{𝑡𝑓121𝑏} homozygotes at three dpf. Whereas cct5^{𝑡𝑓121𝑏} had 48 ± 3 BrdU-positive cells per retinal cross section, 18 ± 1 were proliferating in siblings (n = 5). (D) In contrast to the retina of three-dpf-old siblings, in which apoptotic cells were rarely labelled by the TUNEL assay (green), apoptosis was frequently observed throughout the entire retina of cct5^{𝑡𝑓121𝑏}homozygotes. Data are mean ± SEM; ***P < 0.001 by Student’s t-test. Arrowheads indicate optic nerves (ON).