Two-dimensional electrophoresis of horse serum proteins: genetic polymorphism of ceruloplasmin and two other serum proteins.

Two-dimensional agarose gel (pH 8.6)-horizontal polyacrylamide gel (pH 9.0) electrophoresis of horse serum proteins revealed genetic polymorphism of ceruloplasmin (Cp) and two unidentified serum proteins tentatively designated serum protein 1 (SP1) and serum protein 2 (SP2). Family data were consistent with the hypothesis that the observed Cp and SP1 phenotypes were each controlled by two codominant, autosomal alleles. The three common SP2 phenotypes were shown to be controlled by two codominant, autosomal alleles. Population data and limited family data indicated the occurrence of two additional SP2 alleles. Altogether more than 600 horses representing 13 different breeds were typed for Cp, SP1 and SP2, and allele frequency estimates were calculated. SP2 was highly polymorphic in all breeds studied whereas SP1 and Cp showed quite low degrees of polymorphism. SP1 polymorphism was observed in seven breeds while Cp polymorphism was observed only in the Icelandic toelter horse breed.