Purifying selection during maternal inheritance of mammalian mtDNA depends on autophagy and bottleneck size

Autophagy is identified as a key mediator of purifying selection in mammalian mitochondrial DNA.

• Mitochondrial DNA accumulates mutations at a high rate, which may lead to a mutational meltdown.
• Control animals exhibited mutation patterns similar to those in humans, showing strong purifying selection against non-synonymous mutations in oxidative phosphorylation genes.
• Both mtDNA copy number and autophagy appear to directly influence the efficiency of purifying selection.
• The study suggests that autophagy and mtDNA copy number are functionally interconnected in the context of maternal mtDNA transmission.

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