title: Spatial pattern of adaptive and neutral genetic diversity across different biomes in the lesser anteater (Tamandua tetradactyla).
abstract: The genes of the major histocompatibility complex (MHC) code for proteins involved in antigen recognition and activation of the adaptive immune response and are thought to be regulated by natural selection, especially due to pathogen-driven selective pressure. In this study, we investigated the spatial distribution of MHC class II DRB exon 2 gene diversity of the lesser anteater (Tamandua tetradactyla) across five Brazilian biomes using next-generation sequencing and compared the MHC pattern with that of neutral markers (microsatellites). We found a noticeable high level of diversity in DRB (60 amino acid alleles in 65 individuals) and clear signatures of historical positive selection acting on this gene. Higher allelic richness and proportion of private alleles were found in rain forest biomes, especially Amazon forest, a megadiverse biome, possibly harboring greater pathogen richness as well. Neutral markers, however, showed a similar pattern to DRB, demonstrating the strength of demography as an additional force to pathogen-driven selection in shaping MHC diversity and structure. This is the first characterization and description of diversity of a MHC gene for any member of the magna-order Xenarthra, one of the basal lineages of placental mammals.
authors.affiliation: Laboratório de Biologia Evolutiva e Conservação de Vertebrados Departamento de Genética e Biologia Evolutiva Instituto de Biociências Universidade de São Paulo R. do Matão, 277 05508-090 São Paulo Brasil ; Leibniz-Institute for Zoo and Wildlife Research (IZW) Evolutionary Genetics Alfred- Kowalke-Straße 17 D-10315 Berlin Germany.
authors.forename: Camila L
authors.initials: CL
authors.lastname: Clozato
authors.affiliation: Leibniz-Institute for Zoo and Wildlife Research (IZW) Evolutionary Genetics Alfred- Kowalke-Straße 17 D-10315 Berlin Germany ; Berlin Center for Genomics in Biodiversity Research (BeGenDiv) Koenigin-Luise-Straße. 6-8 D-14195 Berlin Germany.
authors.forename: Camila J
authors.initials: CJ
authors.lastname: Mazzoni
authors.affiliation: Laboratório de Biologia Evolutiva e Conservação de Vertebrados Departamento de Genética e Biologia Evolutiva Instituto de Biociências Universidade de São Paulo R. do Matão, 277 05508-090 São Paulo Brasil ; CIBIO Centro de Investigação em Biodiversidade e Recursos Genéticos InBio Laboratório Associado Universidade do Porto R. Padre Armando Quintas 4485-661 Vairão Portugal.
authors.forename: Nadia
authors.initials: N
authors.lastname: Moraes-Barros
authors.affiliation: Laboratório de Biologia Evolutiva e Conservação de Vertebrados Departamento de Genética e Biologia Evolutiva Instituto de Biociências Universidade de São Paulo R. do Matão, 277 05508-090 São Paulo Brasil.
authors.forename: João S
authors.initials: JS
authors.lastname: Morgante
authors.affiliation: Leibniz-Institute for Zoo and Wildlife Research (IZW) Evolutionary Genetics Alfred- Kowalke-Straße 17 D-10315 Berlin Germany ; Evolutionary Ecology and Conservation Genomics University of Ulm Albert-Einstein Strasse 11 D-89069 Ulm Germany.
authors.forename: Simone
authors.initials: S
authors.lastname: Sommer
keywords: Brazil; DRB; Tamandua tetradactyla; major histocompatibility complex; microsatellites; next‐generation sequencing; selection