Avni Eliran, Snir Sagi
Dept. of Evolutionary Biology, University of Haifa, Haifa 31905, Israel.
Mol Phylogenet Evol. 2017 Nov;116:141-148. doi: 10.1016/j.ympev.2017.08.007. Epub 2017 Aug 24.
Horizontal gene transfer (HGT) is a major part of the evolution of Archaea and Bacteria, to the extent that the validity of the Tree of Life concept for prokaryotes has been seriously questioned. The patterns and routes of HGT remain a subject of intense study and debate. It was discovered that while several genes exhibit rampant HGT across the whole prokaryotic tree of life, others are lethal to certain organisms and therefore cannot be successfully transferred to them. We distinguish between these two classes of genes and show analytically that genes found to be toxic to a specific species (E. coli) also resist HGT in general. Several tools we employ show evidence to support that claim. One of those tools is the quartet plurality distribution (QPD), a mathematical tool that measures tendency to HGT over a large set of genes and species. When aggregated over a collection of genes, it can reveal important properties of this collection. We conclude that evidence of toxicity of certain genes to a wide variety of prokaryotes are revealed using the new tool of quartet plurality distribution.
水平基因转移（HGT）是古菌和细菌进化的一个主要部分，以至于生命树概念对于原核生物的有效性受到了严重质疑。HGT的模式和途径仍然是深入研究和争论的主题。研究发现，虽然一些基因在整个原核生物生命树中呈现出猖獗的HGT，但其他一些基因对某些生物体是致命的，因此无法成功转移到它们身上。我们区分了这两类基因，并通过分析表明，被发现对特定物种（大肠杆菌）有毒的基因通常也会抵抗HGT。我们使用的几种工具都显示出支持这一说法的证据。其中一种工具是四重多数分布（QPD），这是一种数学工具，用于测量一大组基因和物种中的HGT倾向。当对一组基因进行汇总时，它可以揭示该组基因的重要特性。我们得出结论，使用四重多数分布这一新工具揭示了某些基因对多种原核生物具有毒性的证据。
