Gweon Hyun S, Bailey Mark J, Read Daniel S
Centre for Ecology & Hydrology, Wallingford, UK.
ISME J. 2017 Mar;11(3):821-824. doi: 10.1038/ismej.2016.142. Epub 2016 Nov 11.
Bacterial genome sizes have previously been shown to exhibit a bimodal distribution. This phenomenon has prompted discussion regarding the evolutionary forces driving genome size in bacteria and its ecological significance. We investigated the level of inherent redundancy in the public database and the effect it has on the shape of the apparent bimodal distribution. Our study reveals that there is a significant bias in the genome sequencing efforts towards a certain group of species, and that correcting the bias using species nomenclature and clustering of the 16S rRNA gene, results in a unimodal rather than the previously published bimodal distribution. The true genome size distribution and its wider ecological implications will soon emerge as we are currently witnessing rapid growth in the number of sequenced genomes from diverse environmental niches across a range of habitats at an unprecedented rate.
此前已表明细菌基因组大小呈现双峰分布。这一现象引发了关于驱动细菌基因组大小的进化力量及其生态意义的讨论。我们研究了公共数据库中固有冗余的水平及其对表观双峰分布形状的影响。我们的研究表明，基因组测序工作对某一组物种存在显著偏差，并且使用物种命名法和16S rRNA基因聚类来校正偏差，会导致单峰分布而非先前发表的双峰分布。随着我们目前以前所未有的速度见证来自一系列栖息地不同环境生态位的测序基因组数量的快速增长，真实的基因组大小分布及其更广泛的生态意义将很快显现出来。
