Figure 4

Sensitivity to DNA damage is increased in unga mutant zebrafish retinas. (a,b) AO staining of control and DEB-treated 2 dpf wild-type embryos shows an increased level of cell death upon the administration of the genotoxic agent. (c,d) DEB-treated unga mutant embryos also show elevated levels of apoptosis. However, unlike in wild-type controls, large clusters of AO-positive cells appear in these animals. Scale bar: 100 μm. (e) Quantification of apoptosis as measured by the number of AO foci in the control and DEB-treated embryos of the relevant genotypes (The Mann–Whitney test was used to calculate the p-values). (f–i) HE staining of the retinal sections of the wild-type and unga mutant embryos reveal that upon DEB treatment, a few dying (or missing) cells can be seen in the wild-type animals (black arrowheads). In contrast, large clusters of cells with apoptotic character are apparent in the mutant retinas (black arrows). Scale bar: 100 μm.