A dog’s life: Scientists find new formula for canine age
washington — A well-known “rule of paw” holds that you can tell how old your pooch is in human terms by multiplying its age in years by seven.
But in fact, the real ratio changes over time, the US National Institutes of Health (NIH) said, following a study of biological changes to dogs’ genomes over the course of their lives.
Dogs, humans and in fact all mammals experience the same developmental timeline: birth, infancy, youth, puberty, adulthood and death.
Scientists have identified chemical marks on the DNA that correspond to these different stages, an area of study called epigenetics. The field is well established
for humans, and some commercial companies let you send in a DNA sample to determine your biological age by reading your “epigenetic clock.”
Molecules called methyl groups attach themselves to a particular region of the DNA, switching them to the “off” position and ushering in the next stage of life.
Trey Ideker of the University of San Diego, who was the senior author of the study published in Cell Systems, likened these patterns to wrinkles on the genome.
“I tend to think of it very much like when you look at someone’s face and guess their age based on their wrinkles, gray hair, and other
“These are just similar kinds of features on the molecular level.”
Ideker and colleagues studied the methylation patterns on 104 Labrador retrievers, who ranged in age from a few weeks old to 16 years. These were then compared to the methylation patterns in humans. —