Does a tree-like phylogeny only exist at the tips in the prokaryotes?
Proc Biol Sci
; 271(1557): 2551-8, 2004 Dec 22.
Article
em En
| MEDLINE
| ID: mdl-15615680
ABSTRACT
The extent to which prokaryotic evolution has been influenced by horizontal gene transfer (HGT) and therefore might be more of a network than a tree is unclear. Here we use supertree methods to ask whether a definitive prokaryotic phylogenetic tree exists and whether it can be confidently inferred using orthologous genes. We analysed an 11-taxon dataset spanning the deepest divisions of prokaryotic relationships, a 10-taxon dataset spanning the relatively recent gamma-proteobacteria and a 61-taxon dataset spanning both, using species for which complete genomes are available. Congruence among gene trees spanning deep relationships is not better than random. By contrast, a strong, almost perfect phylogenetic signal exists in gamma-proteobacterial genes. Deep-level prokaryotic relationships are difficult to infer because of signal erosion, systematic bias, hidden paralogy and/or HGT. Our results do not preclude levels of HGT that would be inconsistent with the notion of a prokaryotic phylogeny. This approach will help decide the extent to which we can say that there is a prokaryotic phylogeny and where in the phylogeny a cohesive genomic signal exists.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Filogenia
/
Bactérias
/
Classificação
/
Genoma Bacteriano
/
Transferência Genética Horizontal
Idioma:
En
Ano de publicação:
2004
Tipo de documento:
Article