Accéder directement au contenu Accéder directement à la navigation
Article dans une revue

Attenuated virulence and genomic reductive evolution in the entomopathogenic bacterial symbiont species, Xenorhabdus poinarii

Abstract : Bacteria of the genus Xenorhabdus are symbionts of soil entomopathogenic nematodes of the genus Steinernema. This symbiotic association constitutes an insecticidal complex active against a wide range of insect pests. Unlike other Xenorhabdus species, Xenorhabdus poinarii is avirulent when injected into insects in the absence of its nematode host. We sequenced the genome of the X. poinarii strain G6 and the closely related but virulent Xenorhabdus doucetiae strain FRM16. G6 had a smaller genome (500-700 kb smaller) than virulent Xenorhabdus strains and lacked genes encoding potential virulence factors (haemolysins, type 5 secretion systems, enzymes involved in the synthesis of secondary metabolites, toxin-antitoxin systems). The genomes of all the X. poinarii strains analysed here had a similar small size. We did not observe the accumulation of pseudogenes, insertion sequences or decrease in coding density usually seen as a sign of genomic erosion driven by genetic drift in host-adapted bacteria. Instead, genome reduction of X. poinarii seems to have been mediated by the excision of genomic blocks from the flexible genome, as reported for the genomes of attenuated free pathogenic bacteria and some facultative mutualistic bacteria growing exclusively within hosts. This evolutionary pathway probably reflects the adaptation of X. poinarii to specific host.
Type de document :
Article dans une revue
Liste complète des métadonnées

Littérature citée [133 références]  Voir  Masquer  Télécharger

https://hal.archives-ouvertes.fr/hal-01837258
Déposant : Archive Ouverte Prodinra <>
Soumis le : jeudi 28 mai 2020 - 12:16:01
Dernière modification le : mercredi 25 novembre 2020 - 16:12:02

Fichier

Ogier 2014 Genome Biol Evol_1....
Fichiers éditeurs autorisés sur une archive ouverte

Identifiants

Citation

Jean-Claude Ogier, Sylvie Pages, Gaelle Bisch, Helene Chiapello, Claudine Médigue, et al.. Attenuated virulence and genomic reductive evolution in the entomopathogenic bacterial symbiont species, Xenorhabdus poinarii. Genome Biology and Evolution, Society for Molecular Biology and Evolution, 2014, 6, pp.1495-1513. ⟨10.1093/gbe/evu119⟩. ⟨hal-01837258⟩

Partager

Métriques

Consultations de la notice

490

Téléchargements de fichiers

199