The Elusive Nature of Adaptive Mitochondrial DNA Evolution of an Arctic Lineage Prone to Frequent Introgression

• Type: Article in International Scientific Journal
• Date: 2014

Authors

Jose Melo Ferreira (Author) Other; Joana Vilela (Author) Other; Miguel M Fonseca (Author) Other; Rute R da Fonseca (Author) Other; Pierre Boursot (Author) Other; Paulo C Alves (Author) FCUP

Journal

Title: Genome Biology and Evolution

Vol. 6

Pages: 886-896

ISSN: 1759-6653

Publisher: Oxford University Press

Indexing

ISI Web of Knowledge - 74 Citations

Scopus - 71 Citations

Scientific classification

FOS: Natural sciences > Earth and related Environmental sciences

Other information

Authenticus ID: P-009-H9E

DOI: 10.1093/gbe/evu059

Abstract (EN): Mitochondria play a fundamental role in cellular metabolism, being responsible for most of the energy production of the cell in the oxidative phosphorylation (OXPHOS) pathway. Mitochondrial DNA (mtDNA) encodes for key components of this process, but its direct role in adaptation remains far from understood. Hares (Lepus spp.) are privileged models to study the impact of natural selection on mitogenomic evolution because 1) species are adapted to contrasting environments, including arctic, with different metabolic pressures, and 2) mtDNA introgression from arctic into temperate species is widespread. Here, we analyzed the sequences of 11 complete mitogenomes (ten newly obtained) of hares of temperate and arctic origins (including two of arctic origin introgressed into temperate species). The analysis of patterns of codon substitutions along the reconstructed phylogeny showed evidence for positive selection in several codons in genes of the OXPHOS complexes, most notably affecting the arctic lineage. However, using theoretical models, no predictable effect of these differences was found on the structure and physicochemical properties of the encoded proteins, suggesting that the focus of selection may lie on complex interactions with nuclear encoded peptides. Also, a cloverleaf structure was detected in the control region only from the arctic mtDNA lineage, which may influence mtDNA replication and transcription. These results suggest that adaptation impacted the evolution of hare mtDNA and may have influenced the occurrence and consequences of the many reported cases of massive mtDNA introgression. However, the origin of adaptation remains elusive.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 11