Journal of Molecular Evolution

, Volume 62, Issue 3, pp 319–331

Molecular Evolution of Cytochrome c Oxidase in High-Performance Fish (Teleostei: Scombroidei)

  • Anne C. Dalziel
  • Christopher D. Moyes
  • Emma Fredriksson
  • Stephen C. Lougheed
Article

DOI: 10.1007/s00239-005-0110-7

Cite this article as:
Dalziel, A.C., Moyes, C.D., Fredriksson, E. et al. J Mol Evol (2006) 62: 319. doi:10.1007/s00239-005-0110-7

Abstract

The 13 peptides encoded by vertebrate mitochondrial DNA (mtDNA) are essential subunits of oxidative phosphorylation (OXPHOS) enzymes. These genes normally experience purifying selection and also coevolve with nuclear-encoded subunits of OXPHOS complexes. However, the role of positive selection on mtDNA evolution is still unclear, as most examples of intergenomic coevolution appear to be the result of compensation by nuclear-encoded genes for mildly deleterious mtDNA mutations, and not simultaneous positive selection in both genomes. Organisms that have experienced strong selective pressures to increase aerobic capacity or adapt to changes in thermal environment may be better candidates in which to examine the impact of positively selected changes on mtDNA evolution. The tuna (suborder Scombroidei, family Scombridae) and billfish (suborder Scombroidei, families Xiphiidae and Istiophoridae) are highly aerobic fish with multiple specializations in muscle energetics, including a high mitochondrial content and regional endothermy. We examined the role of positively selected mtDNA substitutions in the production of these unique phenotypes. Focusing on a catalytic subunit of cytochrome c oxidase (COX II), we found that the rate ratio of nonsynonymous (dN; amino acid changing)-to-synonymous (dS; silent) substitutions was not increased in lineages leading to the tuna but was significantly increased in the lineage preceding the billfish. Furthermore, there are a number of individual positively selected sites that, when mapped onto the COX crystal structure, appear to interact with other COX subunits and may affect OXPHOS function and regulation in billfish.

Keywords

Mitochondrial DNA evolutionPositive selectionCytochrome c oxidaseAerobic energy metabolismEndothermyTunaBillfish

Copyright information

© Springer Science+Business Media, Inc. 2006

Authors and Affiliations

  • Anne C. Dalziel
    • 1
    • 2
  • Christopher D. Moyes
    • 1
  • Emma Fredriksson
    • 1
  • Stephen C. Lougheed
    • 1
  1. 1.Department of BiologyQueen’s UniversityKingstonCanada
  2. 2.Department of Zoology6270 University Boulevard, University of British ColumbiaVancouverCanada