Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, UK.
Sci China Life Sci. 2015 Mar;58(3):223-31. doi: 10.1007/s11427-015-4811-x. Epub 2015 Feb 5.
Meiotic recombination is a deeply conserved process within eukaryotes that has a profound effect on patterns of natural genetic variation. During meiosis homologous chromosomes pair and undergo DNA double strand breaks generated by the Spo11 endonuclease. These breaks can be repaired as crossovers that result in reciprocal exchange between chromosomes. The frequency of recombination along chromosomes is highly variable, for example, crossovers are rarely observed in heterochromatin and the centromeric regions. Recent work in plants has shown that crossover hotspots occur in gene promoters and are associated with specific chromatin modifications, including H2A.Z. Meiotic chromosomes are also organized in loop-base arrays connected to an underlying chromosome axis, which likely interacts with chromatin to organize patterns of recombination. Therefore, epigenetic information exerts a major influence on patterns of meiotic recombination along chromosomes, genetic variation within populations and evolution of plant genomes.
减数分裂重组是真核生物中高度保守的过程，对自然遗传变异模式有深远影响。在减数分裂过程中，同源染色体配对并发生由 Spo11 内切酶产生的 DNA 双链断裂。这些断裂可以作为交叉点修复，导致染色体之间的相互交换。染色体上重组的频率高度可变，例如，异染色质和着丝粒区域很少观察到交叉点。最近在植物中的研究表明，交叉热点发生在基因启动子中，并与特定的染色质修饰有关，包括 H2A.Z。减数分裂染色体也以连接到染色体轴的环基阵列的形式组织，这可能与染色质相互作用以组织重组模式。因此，表观遗传信息对染色体上减数分裂重组、种群内遗传变异和植物基因组进化的模式有很大影响。
