Buard Jérôme, de Massy Bernard
Institute of Human Genetics, UPR1142-CNRS, 141 rue de la Cardonille, 34396 Montpellier cedex 5, France.
Trends Genet. 2007 Jun;23(6):301-9. doi: 10.1016/j.tig.2007.03.014. Epub 2007 Apr 16.
Crossovers (COs) are essential for meiosis and contribute to genome diversity by promoting the reassociation of alleles, and thus improve the efficiency of selection. COs are not randomly distributed but are found at specific regions, or CO hotspots. Recent results have revealed the historical recombination rates and the distribution of hotspots across the human genome. Surprisingly, CO hotspots are highly dynamic, as shown by differences in activity between individuals, populations and closely related species. We propose a role for DNA methylation in preventing the formation of COs, a regulation that might explain, in part, the correlation between recombination rates and GC content in mammals.
交叉互换（COs）对于减数分裂至关重要，它通过促进等位基因的重新组合来增加基因组多样性，从而提高选择效率。COs并非随机分布，而是存在于特定区域，即CO热点。最近的研究结果揭示了人类基因组的历史重组率以及热点的分布情况。令人惊讶的是，CO热点具有高度动态性，这在个体、群体以及亲缘关系密切的物种之间的活性差异中得到了体现。我们提出DNA甲基化在阻止CO形成中发挥作用，这一调控机制可能部分解释了哺乳动物中重组率与GC含量之间的相关性。
