Abstract
Thirty years have passed since it was shown that sheep have two types of haemoglobin (Hb), A and B. Since then a large number of studies have been undertaken; gene frequencies, relations and origins of breeds, biochemistry, correlations with diseases, to mention the most important fields for which these 2 haemoglobins have been utilized. A few years ago, in a number of studies, Vestri and coworkers (Vestri et al. 1983) using chromatographic and biochemical methods together with isoelectric focusing showed that in Italian sheep additional Hb types occurred. These new types are caused by substitutions in the alpha chains, in contrast to the A and B difference which is caused by 7 amino acid substitutions in the beta chain (Huisman et al. 1965). Vestri et al (1983) also proved that the alpha chains in sheep, as in man, horse and goat among others, are controlled by 2 closely linked alpha globin genes.