University of Düsseldorf, Universitätsstr. 1, Düsseldorf 40225, Germany.
Bioessays. 2017 Dec;39(12). doi: 10.1002/bies.201700115. Epub 2017 Oct 25.
The realization that prokaryotes naturally and frequently disperse genes across steep taxonomic boundaries via lateral gene transfer (LGT) gave wings to the idea that eukaryotes might do the same. Eukaryotes do acquire genes from mitochondria and plastids and they do transfer genes during the process of secondary endosymbiosis, the spread of plastids via eukaryotic algal endosymbionts. From those observations it, however, does not follow that eukaryotes transfer genes either in the same ways as prokaryotes do, or to a quantitatively similar degree. An important illustration of the difference is that eukaryotes do not exhibit pangenomes, though prokaryotes do. Eukaryotes reveal no detectable cumulative effects of LGT, though prokaryotes do. A critical analysis suggests that something is deeply amiss with eukaryote LGT theories.
人们认识到,原核生物通过水平基因转移(LGT)自然且频繁地在陡峭的分类学边界上传播基因,这一观点为真核生物也可能如此提供了依据。真核生物确实从线粒体和质体中获得基因,并且在二次内共生过程中,即通过真核藻类内共生体传播质体的过程中,它们也会转移基因。然而,从这些观察结果并不能推断出真核生物以与原核生物相同的方式或在类似的程度上转移基因。一个重要的例证是,真核生物没有表现出原核生物所具有的泛基因组,尽管原核生物确实存在。真核生物没有显示出 LGT 的可检测到的累积效应,尽管原核生物确实存在。批判性分析表明,真核生物的 LGT 理论存在严重问题。