Search results for "bactérie endosymbiotique"
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Happens in the best of subfamilies: establishment and repeated replacements of co-obligate secondary endosymbionts within Lachninae aphids.
2016
SummaryVirtually all aphids maintain an obligate mutualistic symbiosis with bacteria from theBuchneragenus, which produce essential nutrients for their aphid hosts. Most aphids from the Lachninae subfamily have been consistently found to house additional endosymbionts, mainlySerratia symbiotica. This apparent dependence on secondary endosymbionts was proposed to have been triggered by the loss of the riboflavin biosynthetic capability byBuchnerain the Lachninae last common ancestor. However, an integral large-scale analysis of secondary endosymbionts in the Lachninae is still missing, hampering the interpretation of the evolutionary and genomic analyses of these endosymbionts. Here, we anal…
Reinventing the Wheel and Making It Round Again: Evolutionary Convergence in Buchnera-Serratia Symbiotic Consortia between the Distantly Related Lach…
2016
International audience; Virtually all aphids (Aphididae) harbor Buchnera aphidicola as an obligate endosymbiont to compensate nutritional deficiencies arising from their phloem diet. Many species within the Lachninae subfamily seem to be consistently associated also with Serratia symbiotica We have previously shown that both Cinara (Cinara) cedri and Cinara (Cupressobium) tujafilina (Lachninae: Eulachnini tribe) have indeed established co-obligate associations with both Buchnera and S. symbiotica However, while Buchnera genomes of both Cinara species are similar, genome degradation differs greatly between the two S. symbiotica strains. To gain insight into the essentiality and degree of int…
Tempo and mode of early gene loss in endosymbiotic bacteria from insects
2006
Abstract Background Understanding evolutionary processes that drive genome reduction requires determining the tempo (rate) and the mode (size and types of deletions) of gene losses. In this study, we analysed five endosymbiotic genome sequences of the gamma-proteobacteria (three different Buchnera aphidicola strains, Wigglesworthia glossinidia, Blochmannia floridanus) to test if gene loss could be driven by the selective importance of genes. We used a parsimony method to reconstruct a minimal ancestral genome of insect endosymbionts and quantified gene loss along the branches of the phylogenetic tree. To evaluate the selective or functional importance of genes, we used a parameter that meas…