The Phenotype of Sheep Hemoglobins Containing Distinct α Chains Is Influenced by β Chain Genotype

In sheep carrying simultaneously extra α‐globin genes (triplications and quadruplications) and two α‐chain allelic variants, a gradient of decreasing expression of the downstream genes was previously reported. We show here that in these sheep the proportions of the normal and variant Hbs reflect not only the position effect, but also the differential affinity of one of the α variants for the βA and βB allelic chains.