Dogs are an exception to a common pattern among mammals: larger animals often live longer, but large dog breeds tend to age faster and die younger than small breeds. Researchers at Arizona State University say differences in DNA regulation may help explain why, according to a study published in Science.
The scientists analyzed data from 864 dogs in the Dog Aging Project, mapping DNA methylation across their genomes. These chemical markers influence whether genes are switched on or off and can change over time in response to factors such as stress. Unlike DNA sequences, which are largely fixed, methylation patterns can therefore provide clues about aging and gene regulation.
The study linked aging in dogs to declining DNA methylation, especially around “jumping genes”—sequences that can move between chromosomes. Their activity can damage DNA and contribute to cancer and other age-related diseases, the researchers said. The team identified LINE1s, a class of jumping genes, as a factor in differences in aging rates: giant breeds lost roughly 35 percent more LINE1 methylation each year than small breeds.
The findings were among October’s research stories, alongside reports on physicists trapping a single antimatter particle for months and tattoo inks that are visible only under ultraviolet light.
Sources: Ars Technica.