Co-evolution between transposable elements and their hosts: a major factor in genome size evolution?
Co-evolution between transposable elements and their hosts: a major factor in genome size evolution?
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DOI：
10.1007/s10577-011-9229-0
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发表时间：
2011-08-01
影响因子：
2.6
通讯作者：
Wright, Stephen I.
中科院分区：
文献类型：
--
作者：
Agren, J. Arvid;Wright, Stephen I.
基因组大小进化的大多数模型强调插入和缺失的相对速率和/或选择效力的变化。然而，转座因子（TE）是基因组大小进化的主要贡献者，并且由于它们经历了自身的选择性扩张压力，基因组大小的变化可能部分地由TE和它们的宿主之间的共同进化的动力学驱动。在这种观点下，关于允许基因组扩增的条件的预测可能会改变。在这篇综述中，我们概述了TE-宿主协同进化的证据，讨论了这些动力学可以改变的条件，并探讨了基因组大小进化的可能贡献。部分由于我们对通过小RNA进行TE沉默的机制的理解的进步，越来越多的证据表明转座率的进化在驱动基因组扩增和收缩中可能是重要的。与种间杂交和交配系统变化相关的基因组大小和转座子丰度的变化与转座率进化的重要作用一致，尽管其他可能的解释仍然存在。对宿主沉默机制的潜在破坏和/或TE逃避宿主免疫应答的潜在可能的更多理解将提高我们对TE活性变化在驱动基因组大小进化中的重要性的理解。
Most models of genome size evolution emphasize changes in relative rates of and/or the efficacy of selection on insertions and deletions. However, transposable elements (TEs) are a major contributor to genome size evolution, and since they experience their own selective pressures for expansion, genome size changes may in part be driven by the dynamics of co-evolution between TEs and their hosts. Under this perspective, predictions about the conditions that allow for genome expansion may be altered. In this review, we outline the evidence for TE-host co-evolution, discuss the conditions under which these dynamics can change, and explore the possible contribution to the evolution of genome size. Aided partly by advances in our understanding of the mechanisms of TE silencing via small RNAs, there is growing evidence that the evolution of transposition rates can be important in driving genome expansion and contraction. Shifts in genome size and transposon abundance associated with interspecific hybridization and changes in mating system are consistent with an important role for transposition rate evolution, although other possible explanations persist. More understanding of the potential for the breakdown of host silencing mechanisms and/or the potential for TEs to evade host immune responses will improve our understanding of the importance of changes in TE activity in driving genome size evolution.