The Entomopathogenic Bacterial Endosymbionts Xenorhabdus and Photorhabdus: Convergent Lifestyles from Divergent Genomes
نویسندگان
چکیده
Members of the genus Xenorhabdus are entomopathogenic bacteria that associate with nematodes. The nematode-bacteria pair infects and kills insects, with both partners contributing to insect pathogenesis and the bacteria providing nutrition to the nematode from available insect-derived nutrients. The nematode provides the bacteria with protection from predators, access to nutrients, and a mechanism of dispersal. Members of the bacterial genus Photorhabdus also associate with nematodes to kill insects, and both genera of bacteria provide similar services to their different nematode hosts through unique physiological and metabolic mechanisms. We posited that these differences would be reflected in their respective genomes. To test this, we sequenced to completion the genomes of Xenorhabdus nematophila ATCC 19061 and Xenorhabdus bovienii SS-2004. As expected, both Xenorhabdus genomes encode many anti-insecticidal compounds, commensurate with their entomopathogenic lifestyle. Despite the similarities in lifestyle between Xenorhabdus and Photorhabdus bacteria, a comparative analysis of the Xenorhabdus, Photorhabdus luminescens, and P. asymbiotica genomes suggests genomic divergence. These findings indicate that evolutionary changes shaped by symbiotic interactions can follow different routes to achieve similar end points.
منابع مشابه
Antibacterial Activities of Extracellular Metabolites of Symbiotic Bacteria, Xenorhabdus and Photorhabdus Isolated from Entomopathogenic Nematodes
Xenorhabdus and Photorhabdus are members of the family Enterobacteriaceae, and are engaged in a mutualistic association with the entomopathogenic nematodes, Steinernema and Heterorhabditis, respectively. In the present study, the organic fraction of ethyl acetate bacterial crude extracts of the symbiotic bacteria, Xenorhabdus stockiae and Photorhabdus luminescens isolated from entomopathogenic ...
متن کاملDiversity of Xenorhabdus and Photorhabdus spp. and Their Symbiotic Entomopathogenic Nematodes from Thailand
Xenorhabdus and Photorhabdus spp. are bacterial symbionts of entomopathogenic nematodes (EPNs). In this study, we isolated and characterized Xenorhabdus and Photorhabdus spp. from across Thailand together with their associated nematode symbionts, and characterized their phylogenetic diversity. EPNs were isolated from soil samples using a Galleria-baiting technique. Bacteria from EPNs were cultu...
متن کاملMolecular identification and genetic diversity among Photorhabdus and Xenorhabdus isolates
Five bacterial strains were isolated from the hemocoel of the greater wax moth larvae (Galleria mellonella) infected with the entomopathogenic nematodes: Heterorhabditis bacteriophora HP88, Heterorhabditis indicus RM1 and Heterorhabditis sp (S1), Steinernema abbasi and Steinernema sp. (S II). Strains were identified as Photorhabdus luminescens HRM1, P. luminescens HS1, P. luminescens HP88, Xeno...
متن کاملRegulating Alternative Lifestyles in Entomopathogenic Bacteria
Bacteria belonging to the genera Photorhabdus and Xenorhabdus participate in a trilateral symbiosis in which they enable their nematode hosts to parasitize insect larvae. The bacteria switch from persisting peacefully in a nematode's digestive tract to a lifestyle in which pathways to produce insecticidal toxins, degrading enzymes to digest the insect for consumption, and antibiotics to ward of...
متن کاملPhase Variation in Xenorhabdus nematophilus and Photorhabdus luminescens: Differences in Respiratory Activity and Membrane Energization.
Phase variation in Xenorhabdus and Photorhabdus spp. has a significant impact on their symbiotic relationship with entomopathogenic nematodes by altering the metabolic by-products upon which the nematodes feed. The preferential retention of the phase I variant by the infective-stage nematode and its better support for nematode reproduction than phase II indicates its importance in the bacterial...
متن کامل