Polymorphism of Whey2 Protein of Sow's Milk

Abstract Polyacrylamide vertical gel electrophoresis was used to separate an unidentified whey protein variant of sow's milk. The protein which migrates to the area directly below the β -casein fraction of sow's milk was identified as the whey 2 region. The proposed polymorphism appears to be controlled by three codominant alleles labelled Whey 2 A , Whey 2 B , and Whey 2 C , each corresponding to a separate zone within the whey 2 region. Allele A was designated as the fastest migrating, B intermediate, and C the slowest zone. The electrophoretic analysis shows that each allele gives rise to three protein bands, similar to the transferrins in pig serum. After electrophoresis, the homozygous condition appears as a single zone within the whey 2 region comprised of three bands. The heterozygous condition appears as a combination of two zones within the whey 2 region comprised of six bands. A total of six phenotypes is possible and each has been found. Further family studies will be necessary to confirm genetic control of this whey 2 protein polymorphism.