Diversity of the Β-Lactoglobulin Genotypes in

β-lactoglobulin is the major whey protein in ruminant milk. In sheep, three genetic variants have been found (A, B and C) which differ from each other by a single base substitution within exon II of the gene. Various reports have indicated that the B variant is associated with higher milk yields. In this study, we have assessed the genotypic frequencies of both A and B variants in samples from Chios and Cyprus fat-tailed sheep. Although both alleles are present in ovine samples, both the allelic frequencies and genotypic distributions were significantly different between the two sheep breeds, thus reflecting a major intra-species difference regarding the genotype of this gene.