Genetic variation of milk proteins in mice

A survey for qualitative and quantitative variation in milk proteins from 58 inbred strains of mice revealed two electrophoretic variants. One is in a whey acidic protein of milk of YBR mice and the other is in a curd protein of the Asian house mouse, Mus musculus castaneus. The whey acidic protein variant is shown to be under the control of a single Mendelian autosomal gene with alleles expressed in a codominant manner. This gene is designated Wap, is not identical to Eg, is not X linked, and is either unlinked or loosely linked to the coat color genes a and b.