No evidence that sex and transposable elements drive genome size variation in evening primroses
No evidence that sex and transposable elements drive genome size variation in evening primroses
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DOI：
10.1111/evo.12627
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发表时间：
2015-04-01
期刊：
影响因子：
3.3
通讯作者：
Wright, Stephen I.
中科院分区：
文献类型：
--
作者：
Agren, J. Arvid;Greiner, Stephan;Wright, Stephen I.
不同物种的基因组大小差异很大，但尽管有大量的关注，但对于选择性和中性过程在管理这种变异中的相对贡献，几乎没有达成一致意见。性别比率可能在基因组大小进化中发挥重要作用，因为它影响转座元件(TES)的选择和传递的效率。本文采用系统发育比较和全基因组测序的方法，研究了月见草属植物性别和TE含量对基因组大小变异的贡献。我们用流式细胞术测定了30个遗传系统不同物种的基因组大小，发现有性/无性繁殖的差异不能解释基因组大小的几乎两倍的变化。此外，利用基因组大小和生殖系统不同的三个物种的全基因组序列，我们发现基因组大小与TE丰度无关；相反，基因组越大，简单序列重复序列的丰度越高。尽管很久以前就很清楚有性繁殖可能会影响基因组进化的各个方面，特别是TE进化，但它似乎并没有在月见草基因组大小进化中发挥主要作用。
Genome size varies dramatically across species, but despite an abundance of attention there is little agreement on the relative contributions of selective and neutral processes in governing this variation. The rate of sex can potentially play an important role in genome size evolution because of its effect on the efficacy of selection and transmission of transposable elements (TEs). Here, we used a phylogenetic comparative approach and whole genome sequencing to investigate the contribution of sex and TE content to genome size variation in the evening primrose (Oenothera) genus. We determined genome size using flow cytometry for 30 species that vary in genetic system and find that variation in sexual/asexual reproduction cannot explain the almost twofold variation in genome size. Moreover, using whole genome sequences of three species of varying genome sizes and reproductive system, we found that genome size was not associated with TE abundance; instead the larger genomes had a higher abundance of simple sequence repeats. Although it has long been clear that sexual reproduction may affect various aspects of genome evolution in general and TE evolution in particular, it does not appear to have played a major role in genome size evolution in the evening primroses.