The sequence and phylogenesis of the α-globin genes of Barbary sheep ( Ammotragus lervia), goat ( Capra hircus), European mouflon ( Ovis aries musimon) and Cyprus mouflon ( Ovis aries ophion)

Abstract

In order to investigate the polymorphism of α-globin chain of hemoglobin amongst caprines, the linked Iα and IIα globin genes of Barbary sheep ( Ammotragus lervia), goat ( Capra hircus), European mouflon ( Ovis aries musimon), and Cyprus mouflon ( Ovis aries ophion) were completely sequenced, including the 5′ and 3′ untranslated regions. European and Cyprus mouflons, which do not show polymorphic α globin chains, had almost identical α globin genes, whereas Barbary sheep exhibit two different chains encoded by two nonallelic genes. Four different α genes were observed and sequenced in goat, validating previous observations of the existence of allelic and nonallelic polymorphism. As in other vertebrates, interchromosomal gene conversion appears to be responsible for such polymorphism. Evaluation of nucleotide sequences at the level of molecular evolution of the Iα-globin gene family in the caprine taxa suggests a closer relationship between the genus Ammotragus and Capra. Molecular clock estimates suggest sheep-mouflon, goat-aoudad, and ancestor-caprine divergences of 2.8, 5.7, and 7.1 MYBP, respectively.