Intraspecific phylogenetic congruence among multiple symbiont genomes.
Journal Article (Journal Article)
Eukaryotes often form intimate endosymbioses with prokaryotic organisms. Cases in which these symbionts are transmitted cytoplasmically to host progeny create the potential for co-speciation or congruent evolution among the distinct genomes of these partners. If symbionts do not move horizontally between different eukaryotic hosts, strict phylogenetic congruence of their genomes is predicted and should extend to relationships within a single host species. Conversely, even rare 'host shifts' among closely related lineages should yield conflicting tree topologies at the intraspecific level. Here, we investigate the historical associations among four symbiotic genomes residing within an aphid host: the mitochondrial DNA of Uroleucon ambrosiae aphids, the bacterial chromosome of their Buchnera bacterial endosymbionts, and two plasmids associated with Buchnera. DNA sequence polymorphisms provided a significant phylogenetic signal and no homoplasy for each data set, yielding completely and significantly congruent phylogenies for these four genomes and no evidence of horizontal transmission. This study thus provides the first evidence for strictly vertical transmission and 'co-speciation' of symbiotic organisms at the intraspecific level, and represents the lowest phylogenetic level at which such coevolution has been demonstrated. These results may reflect the obligate nature of this intimate mutualism and indicate opportunities for adaptive coevolution among linked symbiont genomes.
Full Text
Duke Authors
Cited Authors
- Funk, DJ; Helbling, L; Wernegreen, JJ; Moran, NA
Published Date
- December 2000
Published In
Volume / Issue
- 267 / 1461
Start / End Page
- 2517 - 2521
PubMed ID
- 11197128
Pubmed Central ID
- PMC1690841
Electronic International Standard Serial Number (EISSN)
- 1471-2954
International Standard Serial Number (ISSN)
- 0962-8452
Digital Object Identifier (DOI)
- 10.1098/rspb.2000.1314
Language
- eng