Understanding the origins and evolutionary trajectories of symbiotic partnerships remains a major challenge. Why are some symbioses lost over evolutionary time whereas others become crucial for survival? Here, we use a quantitative trait reconstruction method to characterize different evolutionary stages in the ancient symbiosis between legumes (Fabaceae) and nitrogen-fixing bacteria, asking ho...

Alphaproteobacteria show a great versatility in adapting to a broad range of environments and lifestyles, with the association between bacteria and plants as one of the most intriguing, spanning from relatively unspecific nonsymbiotic association (as rhizospheric or endophytic strains) to the highly species-specific interaction of rhizobia. To shed some light on possible common genetic features...

Endosymbiotic bacteria from different species can live inside cells of the same eukaryotic organism. Metabolic exchanges occur between host and bacteria but also between different endocytobionts. Since a complete genome annotation is available for both, we built the metabolic network of two endosymbiotic bacteria, Sulcia muelleri and Baumannia cicadellinicola, that live inside specific cells of...

Green sulfur bacteria are obligate photolithoautotrophs that require highly reducing conditions for growth and can utilize only a very limited number of carbon substrates. These bacteria thus inhabit a very narrow ecologic niche. However, several green sulfur bacteria have overcome the limits of immobility by entering into a symbiosis with motile Betaproteobacteria in a type of multicellular as...

Highly pleomorphic bacteria have regularly been isolated from mammalian tumors and leukemic bloods. Here, it is shown that highly pleomorphic, cell-wall deficient bacteria derived from a mammalian tumor self-organize in vitro into mammalian tissue-like morphogenetic patterns consisting of multicellular tissue-like sheets and capillary-like networks. It is proposed that these pleomorphic mammali...

Phylogeny and the distribution of symbiotic bacteria in the mixed segment of the wood-eating termite Nasutitermes takasagoensis (Shiraki) were studied. Bacterial 16S rRNA genes (rDNA) were amplified from the mixed segment of the gut by PCR, and two kinds of sequences were identified. The phylogenetic tree was constructed by neighbor-joining and maximum parsimony methods to identify symbionts ha...