Dogs with microphthalmia and/or related eye disorders will be studied using the Microphthamia transcription fector gene (MITF) as a candidate gene. Because this gene causes this problem in mice it seems a reasonable candidate. mRNA from 2 microphthalmic Akitas will be examined and compared to sequence from unaffected dogs which we have already obtained. Families of dogs(3 Great Dane and 5 Australian Shepherd) will be studied to determine if MITF markers co-segregate with eye disorders and/ or merle phenotype. Although we have already obtained the coding sequence of the MITF gene for the melnocyte form, we need to determine the sequence of the promoter region and the form expressed in retinal pigmented epithelium of the eye. With these, we may better understand if the eye defects which occur in homozygous merle dogs are unavoidable or one could select for the pattern and select against the eye anomalies (i.e. are there two or more mutations in MITF with different effects).