Malfroy L, Roth M P, Carrington M, Borot N, Volz A, Ziegler A, Coppin H
Centre d'Immunopathologie et de Génétique Humaine, CNRS UPR 8291, CHUPurpan, Toulouse, France.
Genomics. 1997 Jul 15;43(2):226-31. doi: 10.1006/geno.1997.4800.
Analysis of 784 informative meioses in the CEPH pedigrees revealed a total of 22 recombination events having occurred in the 6-Mb region between D6S265 (70 kb centromeric of HLA-A) and D6S276. These 22 breakpoints were localized with respect to anonymous polymorphic markers, leading to a detailed genetic map of the region telomeric to the human major histocompatibility complex. A nonrandom pattern of recombination was observed throughout this region: the low recombination rate of 0.19% within the 4-Mb interval centromeric to the HLA class I-like candidate gene for hemochromatosis indeed contrasts with the approximate 1% rate observed within the most telomeric two megabases. This reduced rate of recombination may be due to selective constraints depending on environmental factors related to immunity and iron status or to structural variations hampering proper meiotic pairing of homologous sequences. Population data from other human genome segments are now needed to determine whether linkage disequilibrium extending over 4 Mb is unique to this region.
对CEPH家系中784个有效减数分裂的分析显示，在D6S265（位于HLA - A着丝粒侧70 kb处）和D6S276之间的6 Mb区域共发生了22次重组事件。这些22个断点相对于匿名多态性标记进行了定位，从而得到了人类主要组织相容性复合体端粒侧该区域的详细遗传图谱。在整个该区域观察到了非随机的重组模式：在与血色素沉着症的HLA I类样候选基因着丝粒侧4 Mb区间内，重组率低至0.19%，这确实与最端粒侧的2兆碱基内观察到的约1%的重组率形成了对比。这种重组率降低可能是由于与免疫和铁状态相关的环境因素导致的选择性限制，或者是由于阻碍同源序列正确减数分裂配对的结构变异。现在需要来自其他人类基因组片段的群体数据，以确定超过4 Mb的连锁不平衡是否该区域独有的。
