Diversity of symbiotic bacterial communities in terrestrial isopods
2012 Diversity of symbiotic bacterial communities in terrestrial isopods LESMES RODRIGUEZ Lida Carolina (Colombia) firstname.lastname@example.org
Organisation: University of Poitiers, Poitiers (FR) Supervisor : Didier Bouchon & Jessica Dittmer
Summary: Symbiotic bacteria are recognised as important components of arthropod biology given that they play a crucial role in the ecology and evolution of their hosts. In numerous arthropods (e.g. aphids, tse-tse flies, sharpshooters), bacterial symbionts have been shown to provide essential nutrients and/or to confer resistance to pathogens and heat stress to their hosts. Armadillidium vulgare, a crustacean of the order Isopoda, naturally harbours the a-Proteobacterium Wolbachia (reproductive parasite that propagates through vertical transmission). The infection generated by this bacterium induces feminization in terrestrial isopods, and has an important impact on host biology. The objective of this study is to analyse the community structure of bacterial symbionts in the context of Wolbachia infection, in order to test whether Wolbachia has any influence on bacterial community composition or whether the bacterial community has as well any influence on Wolbachia infection. Bacterial communities in Armadillidium vulgare from controlled laboratory lineages and wild populations (Poitou-Charentes - France) were surveyed using genetic fingerprints of partial 16S rRNA gene sequences generated by Temperature Gradient Gel Electrophoresis (TGGE). Results showed that Wolbachia infection has an important impact on bacterial community structure in Armadillidium vulgare. Furthermore, bacterial communities varied depending on infection with different Wolbachia strains. Some bacterial were likewise specific for tissues. For example, we observed specific bands for midgut caeca tissue, allowing the connection of these symbionts with the nutrition function.