Genetic polymorphism of the vitamin D binding protein and another post‐albumin protein in horse serum

Abstract

Horizontal polyacrylamide gel electrophoresis, on 10% separation gel, of horse serum revealed polymorphism of the vitamin D binding protein (Gc protein) and another post-albumin protein (Pa). Family data supported the hypothesis that Gc and Pa types were controlled by autosomal codominant alleles. For both Gc and Pa proteins, the homozygous types showed a single fraction while the heterozygous type had 2 fractions. Pa types were identical to the post-albumin types reported earlier by starch gel electrophoresis. Two Gc alleles, Gc F and Gc S, and 3 Pa alleles, Pa D, Pa F and Pa S, were observed in samples from Swedish (4 breeds), Lipizzaner and Arab horses. The frequency of the more common allele at the 2 loci, i.e., Gc F and Pa F, ranged 0.72-0.93 and 0.58-0.99, respectively, in the different breeds studied. Plasma samples showed an extra protein fraction near the Gc S fraction and were unsuitable for Gc typing.