A phylogenomic study of endosymbiotic bacteria
Författare
Summary, in English
Endosymbiotic bacteria of aphids, Buchnera aphidicola, and tsetse flies, Wigglesworthia glossinidia, are descendents of free-living gamma-Proteobacteria. The acceleration of sequence evolution in the endosymbiont genomes is here estimated from a phylogenomic analysis of the gamma-Proteobacteria. The tree topologies associated with the most highly conserved genes suggest that the endosymbionts form a sister group with Escherichia coli, Salmonella sp., and Yersinia pestis. Our results indicate that deviant tree topologies result from high substitution rates and biased nucleotide patterns, rather than from lateral gene transfer, as previously suggested. A reinvestigation of the relative rate increase in the endosymbiont genomes reveals variability among genes that correlate with host-associated metabolic dependencies. The conclusion is that host-level selection has retarded both the loss of genes and the acceleration of sequence evolution in endocellular symbionts.
Avdelning/ar
Publiceringsår
2004
Språk
Engelska
Sidor
1110-1122
Publikation/Tidskrift/Serie
Molecular biology and evolution
Volym
21
Issue
6
Dokumenttyp
Artikel i tidskrift
Förlag
Oxford University Press
Ämne
- Biological Sciences
Status
Published
Forskningsgrupp
- Microbial Ecology
ISBN/ISSN/Övrigt
- ISSN: 0737-4038