Abstract

Different alleles at the two linked α-globin loci are present in sheep: ^Iα^113Leu and ^IIα^113Leu, ^Iα^8Ala,113Leu, ^Iα^15Asp,113Leu, and ^IIα^113His. Triplicated α-gene haplotypes are also common. Six different β-globins (A, B, E, G, H, and I) contribute to the Hb polymorphism. A comparative study on the biochemical polymorphism of α- and β-globins in pure sheep breeds of the Mediterranean islands of Chios, Cyprus, and Sardinia is described. Cyprus and Sardinia breeds have the lower frequency of α-globin variants. Chios sheep possess the high 0.40 frequency of the ^Iα^{8Ala,113Leu-II}α^113His arrangement. No α-gene triplications were observed amongst Chios and Cyprus breeds. None showed the ^Iα^15Asp,113Leu variant. The β^B allele largely predominates; the frequency of the β^A was lower (f = 0.03) amongst Sarda sheep that also possess the β^I variant. A novel β^B-globin variant was observed in the Chios breed. Both natural and artificial selection may be the cause for these differences.

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