Big brown bats experience slower epigenetic ageing during hibernation

Area of Science:

• Epigenetics
• Comparative Biology
• Mammalian Physiology

Background:

• Species-level studies suggest hibernation correlates with increased longevity in bats.
• The impact of hibernation on individual biological aging remains unclear.

Purpose of the Study:

• To investigate the effect of hibernation on biological aging in the big brown bat (Eptesicus fuscus) using DNA methylation (DNAm).
• To identify epigenetic markers associated with hibernation and aging in bats.

Main Methods:

• Epigenetic age prediction using a multi-species epigenetic clock.
• Paired comparison of DNA methylation in the same individuals during hibernating and active seasons.
• Genome-wide association analysis of differentially methylated positions (DMPs) with functional genomic elements.

Main Results:

• Hibernation was associated with epigenetic age in big brown bats.
• Over 3000 differentially methylated positions (DMPs) were identified between hibernating and active states, independent of chronological age.
• Hibernation-associated DMPs were enriched at quiescent chromatin and transcription enhancer sites, with nearby genes involved in metabolic processes and innate immunity.
• A significant overlap was found between hibernation DMPs and previously identified longevity DMPs.

Conclusions:

• Hibernation influences epigenetic aging in individual bats.
• Epigenetic changes during hibernation suggest mechanisms impacting metabolic regulation and immunity.
• Findings support the hypothesis that hibernation contributes to longevity in bats.