Evolution of toll-like receptors 4 and 7 genes in wild rodents (Murinae)

0374375 - ÚBO 2012 FR eng A - Abstrakt
Fornůsková, Alena - Galan, M. - Cerqueira, F. - Bryja, Josef - Charbonnel, N. - Cosson, J.-F.
Evolution of toll-like receptors 4 and 7 genes in wild rodents (Murinae).
ECM 2011. VIth EuropeanCongress of Mammalogy. Paris: Université P. et M. Curie, 2011 - (Denys, C.). s. 12
[European Congress of Mammalogy /7./. 19.07.2011-23.07.2011, Paris]
Výzkumný záměr: CEZ:AV0Z60930519
Klíčová slova: rodents * toll-like receptors
Kód oboru RIV: EG - Zoologie
http://www.alphavisa.com/ecm2011/pdf/ECM2011-Abstract_Book.pdf

Appropriate recognition of parasites is crucial for effective immune response, ensuring an activation of adequate defense mechanisms. In vertebrates, it has frequently been demonstrated that genes encoding proteins involved in the recognition of pathogens by the adaptive immune system are often subject to intense selection pressures. However, much less information has been provided on the selection acting on the genes of the innate immunity. The aim of this study is therefore to describe natural variation of innate immunity genes involved in parasite recognition in rodents and to look for signatures of past selection. We sequenced TLR4 and TLR7 genes, which are known as key receptors of innate immunity, for 23 rodent species within the subfamily Murinae in Europe, Asia and Africa. Overall, the phylogeny of rodents TLR genes correctly recapitulates the phylogeny of rodents. The sequence analyses show that vertebrate Tlrs are slow-evolving genes. Major parts of these two molecules are evolving under strong purifying selection, which is likely to be mediated by the constraint of maintenance of their function, i.e. the recognition of conserved structure of pathogens. However, we also found the signatures of positive selection in several amino acid sites of the ectodomain in both TLRs. This domain is specifically involved in the detection of pathogens. This pattern could be explained by episodic parasite-mediated selection during the evolutionary history of rodents.
Trvalý link: http://hdl.handle.net/11104/0207312