Signatures of Adaptation in Mitochondrial Genomes of Palearctic Subterranean Voles (Arvicolinae, Rodentia).

Olga Bondareva,Semen Bodrov,Tatyana Petrova,Antonina Smorkatcheva,Natalia Abramson,Evgeny Genelt-Yanovskiy

doi:10.3390/genes12121945

Olga Bondareva, Semen Bodrov + Show 4 more

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https://doi.org/10.3390/genes12121945

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Journal: Genes	Publication Date: Dec 2, 2021
Citations: 7	License type: CC BY 4.0

Affiliation: Zoological Institute, St Petersburg University

Abstract

This study evaluates signatures of selection in the evolution of the mitochondrial DNA of voles, subfamily Arvicolinae, during the colonization of subterranean environments. The comparative sequence analysis of mitochondrial protein-coding genes of eight subterranean vole species (Prometheomys schaposchnikowi, three species of the genus Ellobius: Ellobius talpinus, Ellobius fuscocapillus and Ellobius lutescens, two species of the genus Terricola: Terricola subterraneus and Terricola daghestanicus, Lasiopodomys mandarinus, and Hyperacrius fertilis) and their closest aboveground relatives was applied using codon-substitution models. The highest number of selection signatures was detected in genes ATP8 and CYTB. The relaxation of selection was observed in most mitochondrial DNA protein-coding genes for subterranean species. The largest amount of relaxed genes is discovered in mole voles (genus Ellobius). The number of selection signatures was found to be independent of the evolutionary age of the lineage but fits the degree of specialization to the subterranean niche. The common trends of selective pressures were observed among the evolutionary ancient and highly specialized subterranean rodent families and phylogenetically young lineages of voles. It suggests that the signatures of adaptation in individual mitochondrial protein-coding genes associated with the colonization of the subterranean niche may appear within a rather short evolutionary timespan.

Highlights

Being among the most diverse groups of mammals, rodents have colonized most major terrestrial habitats around the world
Using ProtParCon, we found six amino acid substitutions meeting our search criteria: COX1 Met73Ile, COX3 Ile121Val, ND5 Phe446Leu, CYTB Thr56Ser, CYTB Ile338Val, and CYTB Ala357Thr (Supplementary Table S4)
A list of common genes with sites under positive selection discovered in branch-site MEME analysis includes more than half of the mitochondrial protein-coding genes: ATP8, COX1, CYTB, ND2, ND4, ND5, and ND6

Summary

Introduction

Being among the most diverse groups of mammals, rodents have colonized most major terrestrial habitats around the world. Most species dwell on the surface, yet many species are able to dig complex tunnels where they nest, rest, and shelter from predators These forms are commonly classified as fossorial, i.e., they dig burrows and tunnels yet spend only a part of their active time there. Subterranean rodents represent a powerful study system for testing hypotheses about adaptive evolution during the colonization of a novel and highly contrasting habitat compared to aboveground species. They inhabit an environment characterized by high levels of carbon dioxide, low levels of oxygen, high humidity, and relatively constant temperature [2]

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