Comparison of Xenorhabdus bovienii bacterial strain genomes reveals diversity in symbiotic functions

BMC Genomics

Research Article

Heidi Goodrich-Blair¹  Kristen E. Murfin¹  Amy C. Whooley¹  Jonathan L. Klassen² 

[1] Department of Bacteriology, University of Wisconsin-Madison, 53706, Madison, WI, USA;Department of Molecular & Cell Biology, University of Connecticut, 06269, Storrs, CT, USA;

关键词: Symbiosis;    Competition;    Xenorhabdus;    Steinernema;    Bacteria;    Nematodes;    Insects;    Comparative genomics;   

DOI  :  10.1186/s12864-015-2000-8

 received in 2015-06-19, accepted in 2015-10-03,  发布年份 2015

来源: Springer

【 摘 要 】

BackgroundXenorhabdus bacteria engage in a beneficial symbiosis with Steinernema nematodes, in part by providing activities that help kill and degrade insect hosts for nutrition. Xenorhabdus strains (members of a single species) can display wide variation in host-interaction phenotypes and genetic potential indicating that strains may differ in their encoded symbiosis factors, including secreted metabolites.MethodsTo discern strain-level variation among symbiosis factors, and facilitate the identification of novel compounds, we performed a comparative analysis of the genomes of 10 Xenorhabdus bovienii bacterial strains.ResultsThe analyzed X. bovienii draft genomes are broadly similar in structure (e.g. size, GC content, number of coding sequences). Genome content analysis revealed that general classes of putative host-microbe interaction functions, such as secretion systems and toxin classes, were identified in all bacterial strains. In contrast, we observed diversity of individual genes within families (e.g. non-ribosomal peptide synthetase clusters and insecticidal toxin components), indicating the specific molecules secreted by each strain can vary. Additionally, phenotypic analysis indicates that regulation of activities (e.g. enzymes and motility) differs among strains.ConclusionsThe analyses presented here demonstrate that while general mechanisms by which X. bovienii bacterial strains interact with their invertebrate hosts are similar, the specific molecules mediating these interactions differ. Our data support that adaptation of individual bacterial strains to distinct hosts or niches has occurred. For example, diverse metabolic profiles among bacterial symbionts may have been selected by dissimilarities in nutritional requirements of their different nematode hosts. Similarly, factors involved in parasitism (e.g. immune suppression and microbial competition factors), likely differ based on evolution in response to naturally encountered organisms, such as insect hosts, competitors, predators or pathogens. This study provides insight into effectors of a symbiotic lifestyle, and also highlights that when mining Xenorhabdus species for novel natural products, including antibiotics and insecticidal toxins, analysis of multiple bacterial strains likely will increase the potential for the discovery of novel molecules

【 授权许可】

CC BY   
© Murfin et al. 2015