Polymorphism of Equine Hemoglobin by the Isoelectric Focusing Method

Abstract

With the purpose of improving the utilization efficacy of b1ood types for parentage testing in light breed horses, an equine hemoglobin type was analyzed by the isoelectric focusing method (IEF). The results are as follows: 1. Hemoglobin (Hb) types controlled by autosomal codominant alleles of A and B were detected in the acryl amide gel adjusted a pH value between 5.5 to 7.7 by the IEF. Its genotypes could be classified into three types; AA, AB and BB types. 2. A and B alleles of the Hb type that were detected by the IEF coincied with the B₂ and B₁ alleles of the Hb-α locus reported in the international comparison test on the equine blood type in 1982. 3. The frequencies of the A and B alleles were 0.874 and 0.126 in Thoroughbreds, and 0.818 and 0.182 in Anglo-Arabs, respectively. In Arabs, Ponies and Japan native horses, the frequencies of B allele were about 37-56% higher than that of the Thoroughbreds. And, the calculated probabilities of negating one of the two possible sire in parentage test in the Hb system for Thoroughbreds and Anglo-Arabs were 0.098 and 0.136, respectively. And then, it for light breed horse was 0.116.