title: Evolution of CCL11: genetic characterization in lagomorphs and evidence of positive and purifying selection in mammals.
abstract: The interactions between chemokines and their receptors are crucial for differentiation and activation of inflammatory cells. CC chemokine ligand 11 (CCL11) binds to CCR3 and to CCR5 that in leporids underwent gene conversion with CCR2. Here, we genetically characterized CCL11 in lagomorphs (leporids and pikas). All lagomorphs have a potentially functional CCL11, and the Pygmy rabbit has a mutation in the stop codon that leads to a longer protein. Other mammals also have mutations at the stop codon that result in proteins with different lengths. By employing maximum likelihood methods, we observed that, in mammals, CCL11 exhibits both signatures of purifying and positive selection. Signatures of purifying selection were detected in sites important for receptor binding and activation. Of the three sites detected as under positive selection, two were located close to the stop codon. Our results suggest that CCL11 is functional in all lagomorphs, and that the signatures of purifying and positive selection in mammalian CCL11 probably reflect the protein's biological roles.
authors.affiliation: CIBIO, InBIO - Research Network in Biodiversity and Evolutionary Biology, Universidade do Porto, Campus de Vairão, Vairão, Portugal UMIB/UP - Unidade Multidisciplinar de Investigação Biomédica/Universidade do Porto, Porto, Portugal.
authors.forename: Fabiana
authors.initials: F
authors.lastname: Neves
authors.affiliation: CIBIO, InBIO - Research Network in Biodiversity and Evolutionary Biology, Universidade do Porto, Campus de Vairão, Vairão, Portugal.
authors.forename: Joana
authors.initials: J
authors.lastname: Abrantes
authors.affiliation: CIBIO, InBIO - Research Network in Biodiversity and Evolutionary Biology, Universidade do Porto, Campus de Vairão, Vairão, Portugal Departamento de Biologia, Faculdade de Ciências da Universidade do Porto, Porto, Portugal CITS - Centro de Investigação em Tecnologias de Saúde, CESPU, Gandra, Portugal pjesteves@cibio.up.pt.
authors.forename: Pedro J
authors.initials: PJ
authors.lastname: Esteves
mesh_terms: D000818:Animals; D005075:Biological Evolution; D054413:Chemokine CCL11 / Q000235:genetics / Q000378:metabolism*; D007793:Lagomorpha / Q000276:immunology*; D009154:Mutation / Q000235:genetics; D011817:Rabbits; D054390:Receptors, CCR2 / Q000378:metabolism; D054397:Receptors, CCR3 / Q000378:metabolism; D019713:Receptors, CCR5 / Q000378:metabolism; D012641:Selection, Genetic; D013045:Species Specificity
chemical_list: D054413:Chemokine CCL11; D054390:Receptors, CCR2; D054397:Receptors, CCR3; D019713:Receptors, CCR5
keywords: CCL11; lagomorphs; mammals; positive selection; purifying selection