Mitochondrial-nuclear interactions and accelerated compensatory evolution: evidence from the primate cytochrome C...

Area of Science:

• Evolutionary biology
• Genomics
• Biochemistry

Background:

• Mammalian mitochondrial DNA (mtDNA) evolution is rapid, potentially driven by coadaptation for energy demands.
• However, mtDNA's lack of recombination and high mutation rate can lead to genome degradation.
• Nuclear DNA (nDNA)-encoded mitochondrial proteins may counteract this degradation.

Purpose of the Study:

• To investigate compensatory adaptive evolution in nuclear-encoded mitochondrial proteins in primates.
• To determine if primate mitochondrial genome features accelerate compensatory evolution in nDNA-encoded genes.
• To analyze the role of physical interactions in the cytochrome c oxidase (COX) complex.

Main Methods:

• Phylogenetic analysis of primate mitochondrial and nuclear genes.
• 3D structural analysis of the cytochrome c oxidase (COX) complex.
• Identification of correlated amino acid substitutions at interacting sites.

Main Results:

• Primate mitochondrial genomes exhibit high mutation rates and small effective population sizes.
• Nuclear-encoded COX components show evidence of positive selection.
• Adaptive nDNA changes correlate with and follow mtDNA changes at physically interacting sites.

Conclusions:

• Compensatory adaptive evolution in nDNA-encoded mitochondrial proteins is crucial for primate mitochondrial function.
• Physical interactions within protein complexes drive correlated evolution between mtDNA and nDNA.
• Weak selection acting on compensatory substitutions significantly shapes primate COX evolution.