Skip to main content
Log in

Molecular Evolution of Cytochrome c Oxidase Subunit IV: Evidence for Positive Selection in Simian Primates

  • Published:
Journal of Molecular Evolution Aims and scope Submit manuscript

Abstract.

Cytochrome c oxidase (COX) is a multi-subunit enzyme complex that catalyzes the final step of electron transfer through the respiratory chain on the mitochondrial inner membrane. Up to 13 subunits encoded by both the mitochondrial (subunits I, II, and III) and nuclear genomes occur in eukaryotic organisms ranging from yeast to human. Previously, we observed a high number of amino acid replacements in the human COX IV subunit compared to mouse, rat, and cow orthologues. Here we examined COX IV evolution in the two groups of anthropoid primates, the catarrhines (hominoids, cercopithecoids) and platyrrhines (ceboids), as well as one prosimian primate (lorisiform), by sequencing PCR-amplified portions of functional COX4 genes from genomic DNAs. Phylogenetic analysis of the COX4 sequence data revealed that accelerated nonsynonymous substitution rates were evident in the early evolution of both catarrhines and, to a lesser extent, platyrrhines. These accelerated rates were followed later by decelerated rates, suggesting that positive selection for adaptive amino acid replacement became purifying selection, preserving replacements that had occurred. The evidence for positive selection was especially pronounced along the catarrhine lineage to hominoids in which the nonsynonymous rate was first faster than the synonymous rate, then later much slower. The rates of three types of ``neutral DNA'' nucleotide substitutions (synonymous substitutions, pseudogene nucleotide substitutions, and intron nucleotide substitutions) are similar and are consistent with previous observations of a slower rate of such substitutions in the nuclear genomes of hominoids than in the nuclear genomes of other primate and mammalian lineages.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Author information

Authors and Affiliations

Authors

Additional information

Received: 22 May 1996 / Accepted: 24 November 1996

Rights and permissions

Reprints and permissions

About this article

Cite this article

Wu, W., Goodman, M., Lomax, M. et al. Molecular Evolution of Cytochrome c Oxidase Subunit IV: Evidence for Positive Selection in Simian Primates . J Mol Evol 44 , 477 –491 (1997). https://doi.org/10.1007/PL00006172

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1007/PL00006172

Navigation