Computational inference of scenarios for alpha-proteobacterial genome evolution.

ABSTRACT: The alpha-proteobacteria, from which mitochondria are thought to have originated, display a 10-fold genome size variation and provide an excellent model system for studies of genome size evolution in bacteria. Here, we use computational approaches to infer ancestral gene sets and to quantify the flux of genes along the branches of the alpha-proteobacterial species tree. Our study reveals massive gene expansions at branches diversifying plant-associated bacteria and extreme losses at branches separating intracellular bacteria of animals and humans. Alterations in gene numbers have mostly affected functional categories associated with regulation, transport, and small-molecule metabolism, many of which are encoded by paralogous gene families located on auxiliary chromosomes. The results sugge

SUBMITTER: Boussau B 

PROVIDER: S-EPMC470742 | biostudies-literature | 2004 Jun

REPOSITORIES: biostudies-literature