Gene transfer in bacteria: Speciation without species?
Gene transfer in bacteria: Speciation without species?
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DOI：
10.1006/tpbi.2002.1587
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发表时间：
2002-06-01
影响因子：
1.4
通讯作者：
Lawrence, JG
中科院分区：
文献类型：
--
作者：
Lawrence, JG
虽然细菌和古生菌通过二次分裂进行繁殖，但谱系之间的基因交换塑造了它们种群的多样性和它们谱系的多样性。基因交换可以通过两种不同的途径发生，每一种途径都对受体基因组产生不同的影响。首先，同源重组介导了密切相关个体之间的DNA交换(那些序列类似地足以实现有效整合的个体)。因此，同源重组介导了优势等位基因的传播，这些优势等位基因可能通过周期性的选择事件在遗传相关的个体中上升到高频率。其次，横向基因转移可以通过非法重组将完全不相关的血统中的新DNA引入基因组。通过这种途径进行的基因交换用于将基因分布在远亲分支中，因此可能赋予受体生物体复杂的能力--在密切相关的谱系中找不到的其他能力。这两种基因交换机制在将微生物种群多样化为独立的、生态上截然不同的谱系方面发挥了互补的作用。尽管微生物“物种”的描述变得困难--如果不是不可能的--但一个令人信服的物种形成过程是可以预测的。(C)2002年埃尔塞维尔科学公司(美国)。
Although Bacteria and Archaea reproduce by binary fission, exchange of genes among lineages has shaped the diversity of their populations and the diversification of their lineages. Gene exchange can occur by two distinct routes, each differentially impacting the recipient genome. First, homologous recombination mediates the exchange of DNA between closely related individuals (those whose sequences are sufficient similarly to allow efficient integration). As a result, homologous recombination mediates the dispersal of advantageous alleles that may rise to high frequency among genetically related individuals via periodic selection events. Second, lateral gene transfer can introduce novel DNA into a genome from completely unrelated lineages via illegitimate recombination. Gene exchange by this route serves to distribute genes throughout distantly related clades and therefore may confer complex abilities-not otherwise found among closely related lineages-onto the recipient organisms. These two mechanisms of gene exchange play complementary roles in the diversification of microbial populations into independent, ecologically distinct lineages. Although the delineation of microbial "species" then becomes difficult-if not impossible-to achieve, a cogent process of speciation can be predicted. (C) 2002 Elsevier Science (USA).