Genome-wide expression dynamics of a marine virus and host reveal features of co-evolution
Genome-wide expression dynamics of a marine virus and host reveal features of co-evolution
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DOI：
10.1038/nature06130
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发表时间：
2007-09-06
期刊：
影响因子：
64.8
通讯作者：
Chisholm, Sallie W.
中科院分区：
文献类型：
--
作者：
Lindell, Debbie;Jaffe, Jacob D.;Chisholm, Sallie W.
细菌宿主和它们的病毒(噬菌体)之间的相互作用通过一个动态的共同进化过程导致互惠的基因组进化(1-5)。噬菌体介导的宿主基因转移通常位于基因组岛上-已经对微生物进化产生了重大影响(1，4，6)。此外，噬菌体基因组显然是通过从宿主获得基因而形成的(2，3，5)。在这里，我们研究了宿主和噬菌体，海洋蓝藻原氯球菌MED4和T7样噬菌体P-SSP7在裂解感染期间的全基因组表达，以深入了解这些共同进化过程。虽然大部分噬菌体基因组在感染过程中是线性转录的，但四个噬菌体编码的细菌代谢基因组成了同一表达簇的一部分，尽管它们在基因组上物理上是分开的。这些基因编码光系统II D1(PSBA)、强光诱导蛋白(Hli)、转醛酶(Talc)和核糖核苷酸还原酶(Nrd)，它们与噬菌体DNA复制基因一起转录，似乎构成了一个功能单位，参与在资源匮乏的海洋中复制噬菌体的能量和脱氧核苷酸的产生。这个系统的另一个独特之处是在感染期间宿主中许多基因的上调。这些可能是宿主应激反应基因和/或由噬菌体诱导的基因。其中许多寄主基因位于基因组岛上，并在噬藻体基因组中有同源基因。我们假设，噬菌体已经进化到使用上调的宿主基因，导致它们稳定地整合到噬菌体基因组中，并随后转移回基因组岛上的宿主。因此，宿主基因在感染过程中的激活可能引导宿主基因组和噬菌体基因组中基因内容的共同进化。
Interactions between bacterial hosts and their viruses ( phages) lead to reciprocal genome evolution through a dynamic co-evolutionary process(1-5). Phage-mediated transfer of host genes often located in genome islands-has had a major impact on microbial evolution(1,4,6). Furthermore, phage genomes have clearly been shaped by the acquisition of genes from their hosts(2,3,5). Here we investigate whole-genome expression of a host and phage, the marine cyanobacterium Prochlorococcus MED4 and the T7-like cyanophage P-SSP7, during lytic infection, to gain insight into these co-evolutionary processes. Although most of the phage genome was linearly transcribed over the course of infection, four phage-encoded bacterial metabolism genes formed part of the same expression cluster, even though they are physically separated on the genome. These genes-encoding photosystem II D1 ( psbA), high-light inducible protein (hli), transaldolase (talC) and ribonucleotide reductase (nrd)-are transcribed together with phage DNA replication genes and seem to make up a functional unit involved in energy and deoxynucleotide production for phage replication in resource-poor oceans. Also unique to this system was the upregulation of numerous genes in the host during infection. These may be host stress response genes and/or genes induced by the phage. Many of these host genes are located in genome islands and have homologues in cyanophage genomes. We hypothesize that phage have evolved to use upregulated host genes, leading to their stable incorporation into phage genomes and their subsequent transfer back to hosts in genome islands. Thus activation of host genes during infection may be directing the co-evolution of gene content in both host and phage genomes.