Evolutionary Origins of Genomic Repertoires in Bacteria

• DOI: 10.1371/journal.pbio.0030130
• Publication Date: 2005-03-30T19:50:57Z
• Authors: Emmanuelle Lerat; Vincent Daubin; Howard Ochman; Nancy A Moran
• Keywords: Human evolutionary genetics

Explaining the diversity of gene repertoires has been a major problem in modern evolutionary biology. In eukaryotes, this is believed to result mainly from duplication and loss, but prokaryotes, lateral transfer (LGT) can also contribute substantially genome contents. To determine histories inventories, we conducted an exhaustive analysis phylogenies for all families widely sampled group, γ-Proteobacteria. We show that, although these bacterial genomes display striking differences repertoires, most having representatives several species have congruent histories. Other than few vast multigene families, contributed relatively little contents genomes; instead, LGT, over time, provides genomic repertoires. Most such acquired genes are lost, majority those that persist transmitted strictly vertically. Although our analyses limited γ-Proteobacteria, results resolve long-standing paradox—i.e., ability make robust phylogenetic inferences light substantial LGT.