Genetic Polymorphism in Caseins of Cow's Milk. I. Genetic Control of α-Casein Variation

Caseins from milk of individual cows were studied by starch-gel-urea electrophoresis. The results indicate that a~-easein, the calcium sensitive component of a-casein, occurs in at least three major forms. Family studies indicate that this variation is controlled by three allelic autosomal genes with no dominance. Each allele is responsible for the production of one of the three forms of a,casein which are designated A, B, and C in order of decreasing mobility. Milk from individual cows may contain any one or any two of these. The six possible types and their corresponding genotypes are: A (A/A), B (B/B), C (C/C), AB (A/B), AC (A/C), and BC (B/C).