Unité Mixte de Recherche, Centre National de Recherche Scientifique 7138, Systématique, Adaptation, Evolution, Université Pierre et Marie Curie, 75005 Paris, France.
Proc Natl Acad Sci U S A. 2010 Jan 5;107(1):127-32. doi: 10.1073/pnas.0908978107. Epub 2009 Dec 10.
DNA flows between chromosomes and mobile elements, following rules that are poorly understood. This limited knowledge is partly explained by the limits of current approaches to study the structure and evolution of genetic diversity. Network analyses of 119,381 homologous DNA families, sampled from 111 cellular genomes and from 165,529 phage, plasmid, and environmental virome sequences, offer challenging insights. Our results support a disconnected yet highly structured network of genetic diversity, revealing the existence of multiple "genetic worlds." These divides define multiple isolated groups of DNA vehicles drawing on distinct gene pools. Mathematical studies of the centralities of these worlds' subnetworks demonstrate that plasmids, not viruses, were key vectors of genetic exchange between bacterial chromosomes, both recently and in the past. Furthermore, network methodology introduces new ways of quantifying current sampling of genetic diversity.
DNA 在染色体和移动元件之间流动，遵循着人们知之甚少的规则。目前用于研究遗传多样性的结构和进化的方法存在局限性，这在一定程度上解释了这种有限的认识。对从 111 个细胞基因组和 165529 个噬菌体、质粒和环境病毒组序列中采样的 119381 个同源 DNA 家族进行网络分析，提供了具有挑战性的见解。我们的研究结果支持遗传多样性的一种不连续但高度结构化的网络，揭示了多个“遗传世界”的存在。这些分裂定义了多个利用不同基因库的独立 DNA 载体组。对这些世界子网的中心性的数学研究表明，质粒而不是病毒，是细菌染色体之间遗传交换的关键载体，无论是在最近还是在过去。此外，网络方法学引入了量化当前遗传多样性采样的新方法。
