Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks St, Toronto, Ontario, Canada M5S3B2.
Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks St, Toronto, Ontario, Canada M5S3B2
Philos Trans R Soc Lond B Biol Sci. 2017 Dec 19;372(1736). doi: 10.1098/rstb.2016.0458.
One of the most striking patterns of genome structure is the tight, typically negative, association between transposable elements (TEs) and meiotic recombination rates. While this is a highly recurring feature of eukaryotic genomes, the mechanisms driving correlations between TEs and recombination remain poorly understood, and distinguishing cause versus effect is challenging. Here, we review the evidence for a relation between TEs and recombination, and discuss the underlying evolutionary forces. Evidence to date suggests that overall TE densities correlate negatively with recombination, but the strength of this correlation varies across element types, and the pattern can be reversed. Results suggest that heterogeneity in the strength of selection against ectopic recombination and gene disruption can drive TE accumulation in regions of low recombination, but there is also strong evidence that the regulation of TEs can influence local recombination rates. We hypothesize that TE insertion polymorphism may be important in driving within-species variation in recombination rates in surrounding genomic regions. Furthermore, the interaction between TEs and recombination may create positive feedback, whereby TE accumulation in non-recombining regions contributes to the spread of recombination suppression. Further investigation of the coevolution between recombination and TEs has important implications for our understanding of the evolution of recombination rates and genome structure.This article is part of the themed issue 'Evolutionary causes and consequences of recombination rate variation in sexual organisms'.
基因组结构最显著的模式之一是转座元件 (TEs) 与减数分裂重组率之间的紧密、通常为负相关关系。尽管这是真核生物基因组中高度重复的特征，但驱动 TE 与重组之间相关性的机制仍知之甚少，区分因果关系具有挑战性。在这里，我们回顾了 TE 与重组之间关系的证据，并讨论了潜在的进化力量。迄今为止的证据表明，总体 TE 密度与重组呈负相关，但这种相关性在元件类型之间存在差异，并且模式可能会反转。结果表明，针对异位重组和基因破坏的选择强度的异质性可以驱动低重组区域中 TE 的积累，但也有强有力的证据表明 TE 的调控可以影响局部重组率。我们假设 TE 插入多态性可能在驱动周围基因组区域中重组率的种内变异方面很重要。此外，TE 和重组之间的相互作用可能会产生正反馈，即非重组区域中 TE 的积累有助于重组抑制的传播。进一步研究重组和 TEs 之间的共同进化对我们理解重组率和基因组结构的进化具有重要意义。本文是主题为“有性生物中重组率变化的进化原因和后果”的一部分。
