Atp7a^Mo-vbr, viable brindled, semidominant. This allele arose spontaneously; it was found among mice in a selection experiment with Cattanach's translocation T(X;7)1Ct (now known as Is(In7;X)1Ct)(J:13473). Heterozygous females have a mottled coat of colored and whitish hair in a pattern of somewhat transversely arranged stripes. The vibrissae are curled, and the coat is slightly rippled (J:5146). Hemizygous males are white, have somewhat reduced viability, and are sterile (J:5146). They have aortic aneurysms, reduced breaking strength of skin, and defective crosslinking of skin collagen and aortic elastin (J:5397). Lysyl oxidase activity in skin is markedly lower than in controls (J:5777). There is decreased level of norepinephrine in the brain as in brindled and blotchy males (J:5373). Evidence of a maternal influence on Atp7a^Mo-vbr coat color, probably due to differing levels of copper in the milk, has been found (J:6573).