Detection by reversed-phase hplc of trace amounts of the α113His globin chain in a sheep homozygous for a quadruple α-globin gene chromosome

1.1. In sheep αα113His and αDαα113His globin gene haplotypes, the percentage gene efficiencies, from the 5' to the 3' end, are about 32-18 and 30-14-6, respectively.2.2. We previously found that in a αααα homozygote there may be a 1–2% α113His chains, which however were difficult to resolve from ga113Leu chains by CMC chromatography.3.3. We report here the experimental conditions which allowed a neat resolution of the 1% α113His chain peak by RP-HPLC.4.4. This finding strongly suggests the occurrence of the αDααα113His haplotype where the percentage gene efficiencies are 30-(14-5)-1, supporting the existence of a gradient of decreasing expression in multiple α-globin gene haplotypes.