The Small Nuclear Genomes of Selaginella Are Associated with a Low Rate of Genome Size Evolution.
The Small Nuclear Genomes of Selaginella Are Associated with a Low Rate of Genome Size Evolution.
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DOI：
10.1093/gbe/evw091
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发表时间：
2016-06-03
影响因子：
3.3
通讯作者：
Barker MS
中科院分区：
文献类型：
--
作者：
Baniaga AE;Arrigo N;Barker MS
维管陆生植物的单倍体核基因组大小（1C DNA）在几个数量级上变化。这种观察到的基因组大小的多样性大部分是由于转座因子的增殖和缺失。到目前为止，所有具有极小核基因组的维管陆地植物谱系代表最近衍生的状态，其祖先具有大得多的基因组大小。卷柏科代表了一个古老的谱系，基因组非常小。目前还不清楚卷柏属的小核基因组是如何进化的。我们比较了卷柏属和主要维管植物分支的核基因组大小进化的速率在比较系统发育框架。为了进行分析，我们收集了29个新的流式细胞术估计的卷柏属单倍体基因组大小，以增加公开可用的数据。卷柏属具有一些已知的最小的单倍体核基因组大小，以及在我们的分析中所包括的所有维管陆地植物中观察到的最低的基因组大小进化速率。此外，我们的分析提供了强有力的支持历史的单倍体核基因组大小停滞卷柏属。我们的研究结果表明，卷柏属，类似于其他早期分歧的血管陆地植物谱系，具有相对较低的基因组大小的进化率。此外，我们的分析强调，快速过渡到一个小的基因组大小只是一个非常小的基因组的途径之一。
The haploid nuclear genome size (1C DNA) of vascular land plants varies over several orders of magnitude. Much of this observed diversity in genome size is due to the proliferation and deletion of transposable elements. To date, all vascular land plant lineages with extremely small nuclear genomes represent recently derived states, having ancestors with much larger genome sizes. The Selaginellaceae represent an ancient lineage with extremely small genomes. It is unclear how small nuclear genomes evolved in Selaginella. We compared the rates of nuclear genome size evolution in Selaginella and major vascular plant clades in a comparative phylogenetic framework. For the analyses, we collected 29 new flow cytometry estimates of haploid genome size in Selaginella to augment publicly available data. Selaginella possess some of the smallest known haploid nuclear genome sizes, as well as the lowest rate of genome size evolution observed across all vascular land plants included in our analyses. Additionally, our analyses provide strong support for a history of haploid nuclear genome size stasis in Selaginella. Our results indicate that Selaginella, similar to other early diverging lineages of vascular land plants, has relatively low rates of genome size evolution. Further, our analyses highlight that a rapid transition to a small genome size is only one route to an extremely small genome.