| multiple origins of endosymbiosis within the enterobacteriaceae (gamma-proteobacteria): convergence of complex phylogenetic approaches. | abstract: background: the bacterial family enterobacteriaceae gave rise to a variety of symbiotic forms, from the loosely associated commensals, often designated as secondary (s) symbionts, to obligate mutualists, called primary (p) symbionts. determination of the evolutionary processes behind this phenomenon has long been hampered by the unreliability of phylogenetic reconstructions within this group of bacteria. the main reasons have been the absence of sufficient data, the highly derived nat ... | 2011 | 22201529 |
| reductive genome evolution, host-symbiont co-speciation and uterine transmission of endosymbiotic bacteria in bat flies. | bat flies of the family nycteribiidae are known for their extreme morphological and physiological traits specialized for ectoparasitic blood-feeding lifestyle on bats, including lack of wings, reduced head and eyes, adenotrophic viviparity with a highly developed uterus and milk glands, as well as association with endosymbiotic bacteria. we investigated japanese nycteribiid bat flies representing 4 genera, 8 species and 27 populations for their bacterial endosymbionts. from all the nycteribiid s ... | 2011 | 21938025 |
| genome sequences of the human body louse and its primary endosymbiont provide insights into the permanent parasitic lifestyle. | as an obligatory parasite of humans, the body louse (pediculus humanus humanus) is an important vector for human diseases, including epidemic typhus, relapsing fever, and trench fever. here, we present genome sequences of the body louse and its primary bacterial endosymbiont candidatus riesia pediculicola. the body louse has the smallest known insect genome, spanning 108 mb. despite its status as an obligate parasite, it retains a remarkably complete basal insect repertoire of 10,773 protein-cod ... | 2010 | 20566863 |
| mutational meltdown in primary endosymbionts: selection limits muller's ratchet. | primary bacterial endosymbionts of insects (p-endosymbionts) are thought to be undergoing the process of muller's ratchet where they accrue slightly deleterious mutations due to genetic drift in small populations with negligible recombination rates. if this process were to go unchecked over time, theory predicts mutational meltdown and eventual extinction. although genome degradation is common among p-endosymbionts, we do not observe widespread p-endosymbiont extinction, suggesting that muller's ... | 2009 | 19305500 |
| evolutionary relationships of "candidatus riesia spp.," endosymbiotic enterobacteriaceae living within hematophagous primate lice. | the primary endosymbiotic bacteria from three species of parasitic primate lice were characterized molecularly. we have confirmed the characterization of the primary endosymbiont (p-endosymbiont) of the human head/body louse pediculus humanus and provide new characterizations of the p-endosymbionts from pediculus schaeffi from chimpanzees and pthirus pubis, the pubic louse of humans. the endosymbionts show an average percent sequence divergence of 11 to 15% from the most closely related known ba ... | 2007 | 17220259 |
| arsenophonus, an emerging clade of intracellular symbionts with a broad host distribution. | the genus arsenophonus is a group of symbiotic, mainly insect-associated bacteria with rapidly increasing number of records. it is known from a broad spectrum of hosts and symbiotic relationships varying from parasitic son-killers to coevolving mutualists.the present study extends the currently known diversity with 34 samples retrieved mainly from hippoboscid (diptera: hippoboscidae) and nycteribiid (diptera: nycteribiidae) hosts, and investigates phylogenetic relationships within the genus. | 2009 | 19619300 |
| symbiotic bacteria associated with stomach discs of human lice. | the symbiotic bacteria associated with the stomach disc, a large aggregate of bacteriocytes on the ventral side of the midgut, of human body and head lice were characterized. molecular phylogenetic analysis of 16s rrna gene sequences showed that the symbionts formed a distinct and well-defined clade in the gammaproteobacteria. the sequences exhibited at-biased nucleotide composition and accelerated molecular evolution. in situ hybridization revealed that in nymphs and adult males, the symbiont w ... | 2006 | 16950915 |