Mutation of pmela resulted in RPE hypopigmentation and eye deficiency at 60 and 90 dpf. (A–D) The pmela^−/− and pmela^−/−;pmelb^−/− mutants showed deep red color in RPE, but difficult to be distinguished from the lateral view. While deep black color was detected in the RPE of wild-type fish and pmelb^−/− mutants. No black pigmentation was detected in the iris of pmela^−/− and pmela^−/−;pmelb^−/− mutants, but some black pigmentation was detected in the iris of pmelb^−/− mutants. (B’ and D’) Additionally, the pmela^−/− (6/20) and pmela^−/−;pmelb^−/− (6/19) mutants were detected with serious eye deficiency (ocular pigment dispersion and pigmentary glaucoma) in around 1/3 mutants, compared with wild-type fish and pmelb^−/− mutants at 60 dpf. (E) Around 1/3 of the pmela^−/− and pmela^−/−;pmelb^−/− mutants were detected with abnormal eye development at 90 dpf, reflected by some melanin spread out of the round iris (yellow dashed box highlighted by yellow arrow heads). Additionally, even though slow restoration of melanin biosynthesis was observed with individual development, a part of the RPE and iris area was detected with almost no melanin, reflected by blood red color (red dashed box highlighted by red arrow heads, under strong bright field). Generally, this is a phenotype of Krukenberg spindle (pigment stuck to the cornea). (F) The statistical analysis of eye pigmentation, the percentages of pmela^−/− and pmela^−/−;pmelb^−/− mutants were significantly lower than in pmelb^−/− mutants and wild-type fish (P > 0.05). And there was also significant difference between pmelb^−/− mutants and wild-type fish (P < 0.05). Data are expressed as mean ± SD (n = 9). Significant differences in the data between groups were tested by one-way ANOVA and Duncan’s post hoc test. P < 0.05 was considered to be statistically significant, indicated by different letters above the error bar.