Jaramillo Vinicio D Armijos, Sukno Serenella A, Thon Michael R
Instituto Hispano-Luso de Investigaciones Agrarias (CIALE), Departamento de Microbiología y Genética, Universidad de Salamanca, Villamayor, Spain.
BMC Genomics. 2015 Jan 2;16(1):2. doi: 10.1186/1471-2164-16-2.
Horizontal gene transfer (HGT) is the stable transmission of genetic material between organisms by means other than vertical inheritance. HGT has an important role in the evolution of prokaryotes but is relatively rare in eukaryotes. HGT has been shown to contribute to virulence in eukaryotic pathogens. We studied the importance of HGT in plant pathogenic fungi by identifying horizontally transferred genes in the genomes of three members of the genus Colletotrichum.
We identified eleven HGT events from bacteria into members of the genus Colletotrichum or their ancestors. The HGT events include genes involved in amino acid, lipid and sugar metabolism as well as lytic enzymes. Additionally, the putative minimal dates of transference were calculated using a time calibrated phylogenetic tree. This analysis reveals a constant flux of genes from bacteria to fungi throughout the evolution of subphylum Pezizomycotina.
Genes that are typically transferred by HGT are those that are constantly subject to gene duplication and gene loss. The functions of some of these genes suggest roles in niche adaptation and virulence. We found no evidence of a burst of HGT events coinciding with major geological events. In contrast, HGT appears to be a constant, albeit rare phenomenon in the Pezizomycotina, occurring at a steady rate during their evolution.
水平基因转移（HGT）是指遗传物质在生物体之间通过垂直遗传以外的方式进行稳定传递。HGT在原核生物进化中具有重要作用，但在真核生物中相对罕见。HGT已被证明对真核病原体的毒力有贡献。我们通过鉴定炭疽菌属三个成员基因组中的水平转移基因，研究了HGT在植物病原真菌中的重要性。
我们鉴定出了11个从细菌转移到炭疽菌属成员或其祖先中的HGT事件。这些HGT事件包括参与氨基酸、脂质和糖代谢的基因以及裂解酶。此外，使用时间校准的系统发育树计算了推定的最小转移日期。该分析揭示了在盘菌亚门的整个进化过程中，基因从细菌到真菌的持续流动。
通常通过HGT转移的基因是那些经常经历基因复制和基因丢失的基因。其中一些基因的功能表明它们在生态位适应和毒力方面发挥作用。我们没有发现HGT事件的爆发与重大地质事件同时发生的证据。相反，HGT似乎是盘菌亚门中一种持续存在的现象，尽管罕见，在其进化过程中以稳定的速率发生。
