Kostyu D D, Dawson D V, Elias S, Ober C
Department of Immunology, Duke University Medical Center, Durham, North Carolina 27710.
Hum Immunol. 1993 Jul;37(3):135-42. doi: 10.1016/0198-8859(93)90178-4.
Deficits of HLA-A, -B homozygotes observed many years ago in two inbred populations suggested negative selection against HLA homozygotes. To determine whether a similar deficiency would be observed in the S-leut Hutterites, a well-characterized Caucasian isolate of European ancestry, and to determine whether selection operated at the allele, locus, or haplotype level, observed and expected numbers of homozygotes were compared in 852 adult Hutterites. Deficits ranging from 11% to 24% were observed for all five loci examined (HLA-A, -B, -C, -DR, and -DQ). However, these deficits were secondary to, and almost completely accounted for by, a 64% loss of individuals homozygous for the haplotype. There was no evidence of deficits affecting only a single allele or locus. The data indicate strong negative selection against HLA homozygotes. This could be due, at least in part, to decreased fecundability among couples sharing HLA-DR. However, these data suggest that additional selective factors acting at the level of the haplotype also operate in this population.
许多年前在两个近亲繁殖群体中观察到的HLA - A、- B纯合子缺失表明对HLA纯合子存在负选择。为了确定在具有明确特征的欧洲血统的高加索隔离群体S - leut哈特派中是否会观察到类似的缺失情况，以及确定选择是在等位基因、基因座还是单倍型水平上起作用，对852名成年哈特派个体中纯合子的观察数量和预期数量进行了比较。在所检测的所有五个基因座（HLA - A、- B、- C、- DR和 - DQ）中都观察到了11%至24%的缺失。然而，这些缺失是次要的，并且几乎完全是由该单倍型纯合个体64%的减少所导致的。没有证据表明缺失仅影响单个等位基因或基因座。数据表明对HLA纯合子存在强烈的负选择。这至少部分可能是由于共享HLA - DR的夫妇之间生育能力下降。然而，这些数据表明在该群体中也存在作用于单倍型水平的其他选择因素。
