Soper L A, Stein M B, Passmore H C
Department of Biological Sciences, Rutgers University, Piscataway, NJ 08855.
J Immunol. 1988 Feb 1;140(3):984-90.
Detailed molecular analysis of three wild-derived MHC haplotypes provided evidence for an important role of the E beta recombinational hot spot in the recent evolution of the mouse I region. Examination of RFLP and restriction maps of cloned DNA permitted the mapping of the natural cross-over events in the haplotypes carried by strains B10.GAA37 (w21) and B10.KPB128 (w19) to a fragment of DNA not exceeding 4.1 kb, which lies almost entirely within the intron separating the beta 1 and beta 2 exons of the E beta gene. In the w14 haplotype (strain B10.STC77), which appears to be a natural recombinant between a p-like parental haplotype and another wild-derived haplotype, the site of crossing over can be mapped to a segment between the beta 2 exon of the E beta gene (left border) and the E beta 2 gene (right border). This segment containing the cross-over site in the w14 haplotype includes the E beta hot spot. In addition, the w14 haplotype as well as the standard p haplotype contain a deletion of approximately 1.0 kb in the second intron of the E beta gene, which may represent the product of an unequal cross-over event in a E beta recombinational hot spot.
对三种野生来源的MHC单倍型进行的详细分子分析为Eβ重组热点在小鼠I区近期进化中的重要作用提供了证据。对克隆DNA的RFLP和限制酶图谱的检查允许将B10.GAA37（w21）和B10.KPB128（w19）菌株携带的单倍型中的自然交叉事件定位到一个不超过4.1 kb的DNA片段上，该片段几乎完全位于分隔Eβ基因β1和β2外显子的内含子内。在w14单倍型（B10.STC77菌株）中，它似乎是一个p样亲本单倍型和另一个野生来源单倍型之间的天然重组体，交叉位点可以定位到Eβ基因β2外显子（左边界）和Eβ2基因（右边界）之间的一段区域。这个在w14单倍型中包含交叉位点的片段包括Eβ热点。此外，w14单倍型以及标准p单倍型在Eβ基因的第二个内含子中都有一个约1.0 kb的缺失，这可能代表了Eβ重组热点中不等交叉事件的产物。
