Lee Yuh Chwen G, Karpen Gary H
Division of Biological Systems and Engineering, Lawrence Berkeley National Laboratory, Berkeley, United States.
Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, United States.
Elife. 2017 Jul 11;6:e25762. doi: 10.7554/eLife.25762.
Transposable elements (TEs) are widespread genomic parasites, and their evolution has remained a critical question in evolutionary genomics. Here, we study the relatively unexplored impacts of TEs and provide the first genome-wide quantification of such effects in and . Surprisingly, the spread of repressive epigenetic marks (histone H3K9me2) to nearby DNA occurs at >50% of euchromatic TEs, and can extend up to 20 kb. This results in differential epigenetic states of genic alleles and, in turn, selection against TEs. Interestingly, the lower TE content in compared to correlates with stronger epigenetic effects of TEs and higher levels of host genetic factors known to promote epigenetic silencing. Our study demonstrates that the epigenetic effects of euchromatic TEs, and host genetic factors modulating such effects, play a critical role in the evolution of TEs both within and between species.
转座元件（TEs）是广泛存在的基因组寄生虫，其进化一直是进化基因组学中的关键问题。在这里，我们研究了TEs相对未被探索的影响，并首次在全基因组范围内对其在[具体物种1]和[具体物种2]中的此类效应进行了量化。令人惊讶的是，抑制性表观遗传标记（组蛋白H3K9me2）向附近DNA的扩散发生在超过50%的常染色质TEs中，并且可以延伸至20 kb。这导致基因等位基因的表观遗传状态不同，进而对TEs产生选择作用。有趣的是，与[具体物种2]相比，[具体物种1]中较低的TE含量与TEs更强的表观遗传效应以及已知促进表观遗传沉默的宿主遗传因子的较高水平相关。我们的研究表明，常染色质TEs的表观遗传效应以及调节此类效应的宿主遗传因子在物种内部和物种之间TEs的进化中起着关键作用。
