Climate-driven mitochondrial selection: A test in Australian songbirds

Annika Mae Lamb, Han Ming Gan, Chris Greening, Leo Joseph, Yin Peng Lee, Alejandra Moran-Ordonez, Paul Sunnucks, Alexandra Pavlova

Research output: Contribution to journalArticleResearchpeer-review

15 Citations (Scopus)

Abstract

Diversifying selection between populations that inhabit different environments can promote lineage divergence within species and ultimately drive speciation. The mitochondrial genome (mitogenome) encodes essential proteins of the oxidative phosphorylation (OXPHOS) system and can be a strong target for climate-driven selection (i.e., associated with inhabiting different climates). We investigated whether Pleistocene climate changes drove mitochondrial selection and evolution within Australian birds. First, using phylogeographic analyses of the mitochondrial ND2 gene for 17 songbird species, we identified mitochondrial clades (mitolineages). Second, using distance-based redundancy analyses, we tested whether climate predicts variation in intraspecific genetic divergence beyond that explained by geographic distances and geographic position. Third, we analysed 41 complete mitogenome sequences representing each mitolineage of 17 species using codon models in a phylogenetic framework and a biochemical approach to identify signals of selection on OXPHOS protein-coding genes and test for parallel selection in mitolineages of different species existing in similar climates. Of 17 species examined, 13 had multiple mitolineages (range: 2–6). Climate was a significant predictor of mitochondrial variation in eight species. At least two amino acid replacements in OXPHOS complex I could have evolved under positive selection in specific mitolineages of two species. Protein homology modelling showed one of these to be in the loop region of the ND6 protein channel and the other in the functionally critical helix HL region of ND5. These findings call for direct tests of the functional and evolutionary significance of mitochondrial protein candidates for climate-associated selection.

Original languageEnglish
Pages (from-to)898-918
Number of pages21
JournalMolecular Ecology
Volume27
Issue number4
DOIs
Publication statusPublished - 1 Feb 2018

Keywords

  • avian phylogeography
  • climatic adaptation
  • mitochondrial genome
  • molecular evolution
  • natural selection
  • oxidative phosphorylation

Cite this