Three New Phenotypic Systems in the Blood of Sheep¹

Abstract

Summary Three new phenotypic systems detectable in the blood of sheep by means of the technique of zone electrophoresis in starch gels are described. One of these systems, designated EsA (A or arylesterase), involves a broad, smudge‐like zone of esterase which developed rapidly during staining and was observed in the serum of about ¼ of the animals sampled. The 2 phenotypes, referred to as EsA‐positive and EsA‐negative, are inherited as if controlled by a pair of alleles, EsA + and EsA ‐ , with EsA + being dominant to EsA ‐ . A quick tube test for the diagnosis of the 2 phenotypes is described. It is shown that the 2 phenotypes correspond respectively with the earlier described phenotypes Halon‐high and Halon‐low discovered by Lee in studies of the hydrolytic activity of ovine serum on di‐(2‐chloroethyl) aryl phosphates. A second system, designated CA, involves 2 electrophoretic forms, CA‐F and CA‐S, of erythrocytic carbonic anhydrase observed in 3 phenotypes CA‐F, CA‐FS and CA‐S. The 3 phenotypes are inherited as if controlled by co‐dominant autosomal alleles designated CA F and CA S . Allele CA S was at or near fixation in 6 of the 9 breeds surveyed in this study. This system has its analogue in the earlier described CA system of cattle. The third system, designated X (unknown) protein, involves 3 zones in electrophoresed red cell lysates which were either present together or absent together. The 2 phenotypes, designated X‐positive and X‐negative, are inherited as if controlled by a pair of alleles, X and x , with X being dominant to x. (This nomenclature is tentative and should be changed when the protein involved becomes identified.) The 2 phenotypes were observed in each of the 9 breeds in the population survey.