The impact of long-distance horizontal gene transfer on prokaryotic genome size
The impact of long-distance horizontal gene transfer on prokaryotic genome size
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DOI：
10.1073/pnas.0907584106
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发表时间：
2009-12-22
影响因子：
11.1
通讯作者：
Hogeweg, Paulien
中科院分区：
文献类型：
--
作者：
Cordero, Otto X.;Hogeweg, Paulien
水平基因转移（HGT）是塑造原核基因库的最主要力量之一。这些基因库可以小至细胞内生物体中的大约 200 个基因，也可以大至大型自由生活细菌中的大约 9,000 个基因。在本文中，我们询问来自系统发育较远来源的 HGT 相对于基因库的大小有何影响。使用不同的 HGT 检测方法并关注累积和最近的进化历史，我们发现了大基因组中长距离转移的非线性富集的令人惊讶的模式。此外，我们发现供体和受体基因组的大小之间存在很强的正相关性。我们的结果还表明，远距离水平转移偏向于那些在大基因组中富集的功能组，这表明功能基因含量的趋势和远距离转移的影响是相互依赖的。这些结果强调了微生物中环境和基因组复杂性之间的密切关系，并表明基因内容中的生态信号（而不是系统发育信号）在大基因组细菌中变得相对重要。
Horizontal gene transfer (HGT) is one of the most dominant forces molding prokaryotic gene repertoires. These repertoires can be as small as approximate to 200 genes in intracellular organisms or as large as approximate to 9,000 genes in large, free-living bacteria. In this article we ask what is the impact of HGT from phylogenetically distant sources, relative to the size of the gene repertoire. Using different approaches for HGT detection and focusing on both cumulative and recent evolutionary histories, we find a surprising pattern of nonlinear enrichment of long-distance transfers in large genomes. Moreover, we find a strong positive correlation between the sizes of the donor and recipient genomes. Our results also show that distant horizontal transfers are biased toward those functional groups that are enriched in large genomes, showing that the trends in functional gene content and the impact of distant transfers are interdependent. These results highlight the intimate relationship between environmental and genomic complexity in microbes and suggest that an ecological, as opposed to phylogenetic, signal in gene content gains relative importance in large-genomed bacteria.