The distribution of haemoglobin and blood potassium types in British breeds of sheep

The incidence of the haemoglobin types, A, B and AB, and of the high- and low-potassium blood types has been determined in thirty-three British breeds of sheep. There is no correlation between the haemoglobin types and the potassium types within the breeds. The gene frequencies at the two loci associated with these characters have been estimated for each breed; there is considerable variation at both loci from breed to breed. The hill breeds of sheep have relatively greater frequencies of the gene for haemoglobin A and the high-potassium gene, while low land breeds have relatively greater frequencies for the haemoglobin B gene and the low-potassium gene. When different breeds are compared, a marked correlation is found between the haemoglobin A gene frequency and the high-potassium gene frequency. The possible biological significance of these findings is discussed.