Signatures of diversifying selection and convergence acting on passerine Toll-like receptor 4 in an evolutionary context
| Autor: | Marian Novotný, Arild Johnsen, Tomáš Albrecht, David Hořák, Jan T. Lifjeld, Hana Velová, Josef Bryja, Michal Vinkler, Ondřej Sedláček, Tereza Králová |
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| Rok vydání: | 2018 |
| Předmět: |
Lipopolysaccharides
Models Molecular 0106 biological sciences 0301 basic medicine Protein Conformation Host–pathogen interaction Static Electricity Lymphocyte Antigen 96 Context (language use) Ligands 010603 evolutionary biology 01 natural sciences Birds Evolution Molecular 03 medical and health sciences Convergent evolution biology.animal Genetics Animals Selection Genetic 10. No inequality Ecology Evolution Behavior and Systematics Toll-like receptor Innate immune system biology Phylogenetic tree Microbiota Sequence Analysis DNA Phenotype Immunity Innate Passerine Toll-Like Receptor 4 Lipid A 030104 developmental biology Evolutionary biology Host-Pathogen Interactions Glycolipids Protein Binding |
| Zdroj: | Molecular Ecology. 27:2871-2883 |
| ISSN: | 0962-1083 |
| Popis: | Positive selection acting on Toll‐like receptors (TLRs) has been recently investigated to reveal evolutionary mechanisms of host–pathogen molecular co‐adaptation. Much of this research, however, has focused mainly on the identification of sites predicted to be under positive selection, bringing little insight into the functional differences and similarities among species and a limited understanding of convergent evolution in the innate immune molecules. In this study, we provide evidence of phenotypic variability in the avian TLR4 ligand‐binding region (LBR), the direct interface between host and pathogen molecular structures. We show that 55 passerine species vary substantially in the distribution of electrostatic potential on the surface of the receptor, and based on these distinct patterns, we identified four species clusters. Seven of the 34 evolutionarily nonconservative and positively selected residues correspond topologically to sites previously identified as being important for lipopolysaccharide, lipid IVa or MD‐2 binding. Five of these positions codetermine the identity of the charge clusters. Groups of species that host‐related communities of pathogens were predicted to cluster based on their TLR4 LBR charge. Despite some evidence for convergence among taxa, there were no clear associations between the TLR4 LBR charge distribution and any of the general ecological characteristics compared (migration, latitudinal distribution and diet). Closely related species, however, mostly belonged to the same surface charge cluster indicating that phylogenetic constraints are key determinants shaping TLR4 adaptive evolution. Our results suggest that host innate immune evolution is consistent with Fahrenholz's rule on the cospeciation of hosts and their parasites. |
| Databáze: | OpenAIRE |
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