TheDominant whitemutation in thePMEL17gene does not cause visual impairment in chickens

OBJECTIVE: To examine whether the Dominant white mutation (causing a hypopigmented phenotype in chicken) affects the visual ability and gives rise to ocular abnormalities in chickens (Gallus gallus). PROCEDURE: Chickens homozygous for either the Dominant white mutation or the wild-type alleles were tested in a visual contrast behavioral test and subjected to histological and ophthalmologic examination. RESULTS: There were no differences between the genotypes in the visual contrast behavioral test, and there were no abnormal structures among the Dominant white chickens in the ophthalmic examination. The histological sections from the Dominant white chickens did not differ from the wild-type chicken in structure, photoreceptor density, or RPE pigmentation. CONCLUSIONS: The results indicate that the Dominant white mutation in PMEL17 does not seem to affect the visual ability or eye structures in chickens.