Comparative Analysis of Mammal Genomes Unveils Key Genomic Variability for Human Life Span

Area of Science:

• Genomics
• Evolutionary Biology
• Mammalian Biology

Background:

• Mammalian lifespan varies due to adaptations and ecological factors.
• Genomic elements influencing species and individual longevity are conserved across life.
• Comparative genomics offers insights into evolutionary adaptations related to lifespan.

Purpose of the Study:

• To identify specific amino acid (AA) changes and genes associated with mammalian longevity.
• To investigate the correlation between protein evolution rates and longevity.
• To assess the potential of comparative genomics in interpreting human genome-wide association studies (GWAS).

Main Methods:

• Comparative analysis of protein-coding regions across mammalian phylogeny.
• Identification of amino acid changes distinguishing long- and short-lived mammals.
• Phylogenetic tests to associate AA changes with maximum lifespan.
• Analysis of protein evolution rates and correlation with longevity.
• Assessment of allele frequencies of identified variants in human populations.
• Evaluation of Single Nucleotide Polymorphisms (SNPs) in detected genes for human heritability.

Main Results:

• Discovered 2,737 amino acid changes in 2,004 genes distinguishing long- and short-lived mammals (P=0.003).
• Identified 1,157 amino acid changes significantly associated with maximum lifespan.
• Found that 99.78% of these variants have low allele frequencies (<1%) in humans, making them undetectable by GWAS.
• Identified four additional genes with protein evolution rates correlating with longevity.
• Demonstrated that SNPs in identified genes explain a greater fraction of human lifespan heritability than expected.
• Showed that human longevity-associated proteins are more stable than those from short-lived mammals.

Conclusions:

• Comparative genomics successfully identifies key genetic factors influencing mammalian longevity.
• The study highlights the limitations of GWAS in detecting rare, evolutionarily conserved variants relevant to human lifespan.
• Protein stability is strongly linked to increased lifespan in mammals.
• Comparative genomics can significantly enhance the interpretation of human GWAS for complex traits like longevity.