Inheritance and selection of the mitochondrial genome.

Mitochondrial genomes are maintained across generations despite high mutation rates, with purifying selection preventing deleterious mutation accumulation in Homo sapiens.

• Why it matters: Understanding how mitochondrial DNA remains functional over generations is crucial because its limited repair capacity and maternal inheritance could lead to species extinction due to mutation buildup.
• What they did: Researchers utilized recent technological advances to investigate the molecular and cellular mechanisms, including timing and processes of purifying selection, that preserve mtDNA integrity.
• The result: Findings reveal that purifying selection acts rapidly over a few generations, enabling mtDNA to evolve while remaining compatible with nuclear genome changes, ensuring species survival.