• Media type: E-Article
  • Title: Reductive genome evolution in Buchnera aphidicola
  • Contributor: van Ham, Roeland C. H. J.; Kamerbeek, Judith; Palacios, Carmen; Rausell, Carolina; Abascal, Federico; Bastolla, Ugo; Fernández, Jose M.; Jiménez, Luis; Postigo, Marina; Silva, Francisco J.; Tamames, Javier; Viguera, Enrique; Latorre, Amparo; Valencia, Alfonso; Morán, Federico; Moya, Andrés
  • imprint: Proceedings of the National Academy of Sciences, 2003
  • Published in: Proceedings of the National Academy of Sciences
  • Language: English
  • DOI: 10.1073/pnas.0235981100
  • ISSN: 0027-8424; 1091-6490
  • Origination:
  • Footnote:
  • Description: <jats:p> We have sequenced the genome of the intracellular symbiont <jats:italic>Buchnera aphidicola</jats:italic> from the aphid <jats:italic>Baizongia pistacea</jats:italic> . This strain diverged 80–150 million years ago from the common ancestor of two previously sequenced <jats:italic>Buchnera</jats:italic> strains. Here, a field-collected, nonclonal sample of insects was used as source material for laboratory procedures. As a consequence, the genome assembly unveiled intrapopulational variation, consisting of ≈1,200 polymorphic sites. Comparison of the 618-kb (kbp) genome with the two other <jats:italic>Buchnera</jats:italic> genomes revealed a nearly perfect gene-order conservation, indicating that the onset of genomic stasis coincided closely with establishment of the symbiosis with aphids, ≈200 million years ago. Extensive genome reduction also predates the synchronous diversification of <jats:italic>Buchnera</jats:italic> and its host; but, at a slower rate, gene loss continues among the extant lineages. A computational study of protein folding predicts that proteins in <jats:italic>Buchnera</jats:italic> , as well as proteins of other intracellular bacteria, are generally characterized by smaller folding efficiency compared with proteins of free living bacteria. These and other degenerative genomic features are discussed in light of compensatory processes and theoretical predictions on the long-term evolutionary fate of symbionts like <jats:italic>Buchnera</jats:italic> . </jats:p>
  • Access State: Open Access