POLYMORPHISM IN A CASEIN FRACTION OF SOWS MILK

Polyacrylamide vertical gel electrophoresis was used to separate the caseins of sows' milk. Polymorphism was found in a region of the gels designated Cn3. The Cn3 polymorphism consists of two bands which appear to be controlled by two codominant alleles designated Cn3Aand Cn3B. Homozygotes possess one band and heterozygotes posses both bands of equal intensity giving the following phenotypes: Cn3A, Cn3AB, and Cn3B. A chi-square test for goodness of fit of the observed phenotypes to that expected by the Hardy-Weinberg equilibrium formula and a segregation analysis of eight matings involving 19 female progeny conform to the hypothesis that the Cn3 polymorphism is controlled by two codominant autosomal alleles. Further family studies will be necessary to confirm the genetic control of the Cn3 polymorphism. © 1969 Plenum Publishing Corporation.