Institute for Genome Science, Department of Microbiology & Immunology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
Trends Genet. 2011 Apr;27(4):157-63. doi: 10.1016/j.tig.2011.01.005. Epub 2011 Feb 18.
Horizontal gene transfer is increasingly described between bacteria and animals. Such transfers that are vertically inherited have the potential to influence the evolution of animals. One classic example is the transfer of DNA from mitochondria and chloroplasts to the nucleus after the acquisition of these organelles by eukaryotes. Even today, many of the described instances of bacteria-to-animal transfer occur as part of intimate relationships such as those of endosymbionts and their invertebrate hosts, particularly insects and nematodes, while numerous transfers are also found in asexual animals. Both of these observations are consistent with modern evolutionary theory, in particular the serial endosymbiotic theory and Muller's ratchet. Although it is tempting to suggest that these particular lifestyles promote horizontal gene transfer, it is difficult to ascertain given the nonrandom sampling of animal genome sequencing projects and the lack of a systematic analysis of animal genomes for such transfers.
水平基因转移越来越多地在细菌和动物之间被描述。这种垂直遗传的转移有可能影响动物的进化。一个经典的例子是，真核生物获得线粒体和叶绿体后，这些细胞器的 DNA 转移到细胞核。即使在今天，许多描述的细菌到动物的转移发生在亲密关系中，如内共生体与其无脊椎动物宿主之间的关系，特别是昆虫和线虫，而在无性动物中也发现了许多转移。这两个观察结果都与现代进化理论一致，特别是连续内共生理论和 Muller 的棘轮。尽管人们很容易认为这些特殊的生活方式促进了水平基因转移，但由于动物基因组测序项目的非随机抽样以及缺乏对这些转移的动物基因组的系统分析，很难确定。
