NUMT ("new mighty") hypothesis of longevity.

Area of Science:

• Evolutionary biology
• Genomics
• Gerontology

Background:

• Mitochondrial DNA (mtDNA) plays a crucial role in cellular energy production and aging.
• Nuclear insertions of mitochondrial DNA (NUMTs) are common genomic events with poorly understood functional implications.
• Maximum life span (MLS) varies significantly across species, influenced by complex genetic and environmental factors.

Purpose of the Study:

• To investigate the relationship between maximum life span (MLS) and the abundance of nuclear mitochondrial DNA insertions (NUMTs).
• To explore potential correlations between NUMT characteristics (number, size, density) and MLS in a diverse range of animal species.
• To examine how mtDNA base composition and other physiological factors relate to NUMT abundance and MLS in mammals.

Main Methods:

• Comparative genomic analysis of 17 animal species with fully sequenced mitochondrial and nuclear genomes.
• Quantification of NUMT abundance, total size, and density within nuclear genomes.
• Statistical correlation analysis to assess relationships between MLS, NUMT metrics, mtDNA base composition, body mass, and resting metabolic rate.

Main Results:

• Highly significant positive correlations were observed between MLS and NUMT number, total size, and density across all analyzed animal species.
• In mammals, NUMT abundance showed a positive correlation with the guanine content of mtDNA and negative correlations with adenine and thymine content.
• No significant correlations were found between NUMT abundance and longevity-associated variables such as body mass or resting metabolic rate in mammals.

Conclusions:

• NUMT abundance is a significant genomic factor positively associated with maximum life span across animal species.
• The composition of mtDNA may influence the integration and abundance of NUMTs in the nuclear genome, particularly in mammals.
• NUMT abundance represents a novel correlate of longevity, independent of traditional physiological predictors like metabolic rate and body mass.