For a rough idea of a dog’s physiological age, a popular approach is to simply multiply its actual age by seven, but new research upends this piece of conventional wisdom. Scientists have developed a new molecular tool described as an “epigenetic clock,” which they say offers a more precise picture of a dog’s age in human years by drilling into the rate of molecular changes in their DNA.
The work was carried out by scientists at the University of California San Diego (UCSD) School of Medicine, who worked with genome experts to examine blood samples taken from 105 Labrador retrievers, ranging in age from a few weeks to 16 years old.
The purpose of this was to try and and uncover patterns of change in chemical markers on the DNA that are driven by age. These modifications are created by methyl groups that interact with the DNA molecule and influence which genes are turned on or off, without altering the DNA sequence. These changes can be driven by all kinds of environmental factors, and are referred to as epigenetic changes.
Epigenetics has emerged as a valuable tool for tracking the physiological age of humans, and the UCSD team set out to explore its potential in doing the same for canines. The analysis of the 105 Labradors enabled them to tease out patterns of methylation change that revealed a truer picture of their physilogical age.