title: Molecular and ecological signs of mitochondrial adaptation: consequences for introgression?
abstract: The evolution of the mitochondrial genome and its potential adaptive impact still generates vital debates. Even if mitochondria have a crucial functional role, as they are the main cellular energy suppliers, mitochondrial DNA (mtDNA) introgression is common in nature, introducing variation in populations upon which selection may act. Here we evaluated whether the evolution of mtDNA in a rodent species affected by mtDNA introgression is explained by neutral expectations alone. Variation in one mitochondrial and six nuclear markers in Myodes glareolus voles was examined, including populations that show mtDNA introgression from its close relative, Myodes rutilus. In addition, we modelled protein structures of the mtDNA marker (cytochrome b) and estimated the environmental envelopes of mitotypes. We found that massive mtDNA introgression occurred without any trace of introgression in the analysed nuclear genes. The results show that the native glareolus mtDNA evolved under past positive selection, suggesting that mtDNA in this system has selective relevance. The environmental models indicate that the rutilus mitotype inhabits colder and drier habitats than the glareolus one that can result from local adaptation or from the geographic context of introgression. Finally, homology models of the cytochrome b protein revealed a substitution in rutilus mtDNA in the vicinity of the catalytic fraction, suggesting that differences between mitotypes may result in functional changes. These results suggest that the evolution of mtDNA in Myodes may have functional, ecological and adaptive significance. This work opens perspective onto future experimental tests of the role of natural selection in mtDNA introgression in this system.
authors.affiliation: 1] Centre of Excellence in Evolutionary Research, Division of Ecology and Evolutionary Biology, Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, Finland [2] CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBio Associate Laboratory, Universidade do Porto, Vairão, Portugal.
authors.forename: Z
authors.identifier: 0000000346684922
authors.initials: Z
authors.lastname: Boratyński
authors.affiliation: CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBio Associate Laboratory, Universidade do Porto, Vairão, Portugal.
authors.forename: J
authors.initials: J
authors.lastname: Melo-Ferreira
authors.affiliation: 1] CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBio Associate Laboratory, Universidade do Porto, Vairão, Portugal [2] Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Porto, Portugal [3] Wildlife Biology Program, University of Montana, Missoula, MT, USA.
authors.forename: P C
authors.initials: PC
authors.lastname: Alves
authors.affiliation: 1] Centre of Excellence in Evolutionary Research, Division of Ecology and Evolutionary Biology, Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, Finland [2] 'TFome and Trancriptome Evolution', Universität Leipzig, Leipzig, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Berto
authors.affiliation: Division of Ecology and Evolutionary Biology, Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, Finland.
authors.forename: E
authors.initials: E
authors.lastname: Koskela
authors.affiliation: Computational Bioscience Laboratory, Division of Cell and Molecular Biology, Department of Biological and Environmental Science & Nanoscience Center, University of Jyväskylä, Jyväskylä, Finland.
authors.forename: O T
authors.initials: OT
authors.lastname: Pentikäinen
authors.affiliation: CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBio Associate Laboratory, Universidade do Porto, Vairão, Portugal.
authors.forename: P
authors.initials: P
authors.lastname: Tarroso
authors.affiliation: Computational Bioscience Laboratory, Division of Cell and Molecular Biology, Department of Biological and Environmental Science & Nanoscience Center, University of Jyväskylä, Jyväskylä, Finland.
authors.forename: M
authors.initials: M
authors.lastname: Ylilauri
authors.affiliation: Centre of Excellence in Evolutionary Research, Division of Ecology and Evolutionary Biology, Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, Finland.
authors.forename: T
authors.initials: T
authors.lastname: Mappes
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D003411:Arvicolinae / Q000145:classification / Q000235:genetics* / Q000502:physiology; D045303:Cytochromes b / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics; D017753:Ecosystem; D019143:Evolution, Molecular; D014644:Genetic Variation; D008297:Male; D008928:Mitochondria / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D012641:Selection, Genetic
chemical_list: D004272:DNA, Mitochondrial; D045303:Cytochromes b