Molecular archaeology of the Escherichia coli genome
Molecular archaeology of the Escherichia coli genome
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DOI：
10.1073/pnas.95.16.9413
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发表时间：
1998-08-04
影响因子：
11.1
通讯作者：
Ochman, H
中科院分区：
文献类型：
--
作者：
Lawrence, JG;Ochman, H
大肠杆菌菌株MG 1655的完整序列的可用性提供了第一个机会来评估水平遗传转移对细菌基因组进化的总体影响。我们发现，4,288个ORF中的755个（547.8 kb）已经在至少234次横向转移事件中被引入大肠杆菌基因组，因为该物种在1亿年前（Myr）从沙门氏菌谱系中分化出来。引入基因的平均年龄为14.4万年，产生的转移率16 kb/万年/谱系以来的分歧。尽管大多数获得的基因随后被删除，但保留下来的序列（大约占当前染色体的18%）赋予了允许大肠杆菌的特性。大肠杆菌来探索其他无法到达的生态位。
The availability of the complete sequence of Escherichia coli strain MG1655 provides the first opportunity to assess the overall impact of horizontal genetic transfer on the evolution of bacterial genomes. We found that 755 of 4,288 ORFs (547.8 kb) have been introduced into the E, coli genome in at least 234 lateral transfer events since this species diverged from the Salmonella lineage 100 million years (Myr) ago. The average age of introduced genes was 14.4 Myr, yielding a rate of transfer 16 kb/Myr/lineage since divergence. Although most of the acquired genes subsequently were deleted, the sequences that have persisted (approximate to 18% of the current chromosome) have conferred properties permitting E. coli to explore otherwise unreachable ecological niches.