Gene conversions in the horse alpha-globin gene complex

The sequences of the linked alpha 2- and alpha 1-globin genes of the equineBI and BII haplotypes are greater than 99% identical within a 1.2-kb regionextending from approximately 75 bp upstream of the putative cap site to apoint approximately 150 bp 3' to the poly A addition signal. Differencesbetween the alpha 2 and alpha 1 genes that are common to both haplotypesindicate that a major gene conversion occurred approximately 12 Myr ago andthat this has been followed by shorter, more localized, conversions.Interhaplotype (allelic) comparisons at the alpha loci suggest that the BIand BII haplotypes have probably existed independently greater than orequal to 0.5 Myr and that the alpha 1 genes may have undergone a recentinterchromosomal gene conversion.