Epigenomics, the study of the factors that impact the epigenome, has focused on understanding the relationship between methylation, age, and disease in humans. However, non-human studies, particularly in mice, have the advantage of being able to explore factors that influence aging that are not easily accessible in humans. Dogs, with their intermediate lifespan and remarkable phenotypic plasticity, especially in relation to body size, provide a valuable model for understanding the impact of environmental and physiological factors on the methylome.
In a recent study, researchers set out to measure the impact of age, sex, weight, sterilization, and genetics on the methylome of dogs and wolves in order to better understand the factors that influence the plasticity of the methylomes in canids. DNA was collected from buccal swabs, which are easily accessible through non-invasive methods, and blood samples from a small number of wolves. The researchers used targeted bisulphite sequencing to profile DNA methylation patterns and focused on a panel of probes that capture a small number of loci in the genome that have been shown to be enriched for sites with variable methylation.
The study found that all of the traits examined, along with associated genotypes, had significant impacts on the epigenomes of dogs and wolves. The researchers also developed models that could predict age, sex, sterilization status, and other traits based on DNA methylation profiles. In addition, the study found that certain genotypes moderated the effects of aging on the methylome, suggesting that genetics can play a role in the rate of epigenetic aging.
Overall, the study provides insight into the factors that influence the plasticity of the methylome in canids and highlights the potential for dogs as a model organism for understanding the impact of environmental and physiological factors on the methylome. Further research on the relationship between methylation and aging in dogs could lead to the development of DNA tests that could be offered to the general public and a better understanding of the role of genetics in the rate of epigenetic aging.