Epigenetics Underlies Comparatively Accelerated Molecular Aging in Larger and Male Dogs

Domestic dogs offer a useful model for understanding the biology of aging because their lifespans vary dramatically with body size. Large dogs tend to be shorter lived than their smaller counterparts, but why? Headed by a team at Arizona State University, a study of nearly 900 dogs now suggests that the answer may be written into the animals’ epigenomes.

Research professor Noah Snyder-Mackler, PhD, at Arizona State University School of Life Sciences, and colleagues developed an epigenetic clock that predicted mortality in dogs and showed that epigenetic aging is fastest early in life. The study results indicated that male dogs and larger dogs undergo accelerated molecular aging, with male dogs exhibiting pronounced DNA methylation (DNAm) changes on the X chromosome, and larger animals exhibiting methylation changes at transposable elements (TEs), stretches of DNA that can influence genome stability and gene regulation.