Gene-centric intra- and inter-clade recombination in a context ofEsche-richia colisubpopulations

Abstract

171 29Text 5742 31All rights reserved. No reuse allowed without permission.(which was not peer-reviewed) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity.The copyright holder for this preprint . http://dx.doi.org/10.1101/122713 doi: bioRxiv preprint first posted online Mar. 31, 2017; ABSTRACT 32Escherichia coli is a Gram-negative bacterial species with both great biological diversity and important 33 clinical relevance. To study its population structure in both world-wide and genome-wide scales, we 46 IMPORTANCE 47The concept of bacterial species has debated over decades. The question becomes more important 48 today as human microbiomes and their health relevance are being studied extensively. The human 49 microbiomes where thousands of bacterial species co-habit need to be deciphered at minute details 50 and down to species and subspecies. In this study, we scrutinize the population genomics of E. coli 51 and define two subspecies that are distinct from each other concerning physiology, ecology, and 52 clinical features. As opposed to extensive genetic recombination within subspecies, limited genetic 53 flux between subspecies leads to their phenotypical distinctions and separate evolution paths. We 54 provide a key example illustrating that the divergence of a species into two subspecies depends on 55 recombination efficiency; when the recombination efficiency becomes a barrier the species appears 56 split into two. The E. coli scenario and its molecular mechanisms deserve further exploration in a 57 broader taxa of microbes. 59All rights reserved. No reuse allowed without permission.(which was not peer-reviewed) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity.