Figure 1

Examples of various types of coat color abnormalities seen in knockout mice. Mc1r knockout mice (A, left) have uniformly hypopigmented strawberry blonde coat color compared with wild type C57BL/6N (A, right) control mice. Mice with targeted deletion of the Dct gene have a brown-colored coat (B,B’, left) compared with wild type C57BL/6N (B,B’, right) control mice. Knockout mice with a white patch on the abdomen have been observed with variable penetrance. Just three of eight Endog knockout mice were found to have a white patch on the belly (C,C’), which may be sporadic, or may represent reduced penetrance related to the targeted deletion.