LINE1 statements
Scientists have announced that they have found the answer to why large dogs age faster than small dogs. According to the research, the answer lies in “jumping” genes called LINE1, which can copy themselves and insert into the genome.
DNA explanations
These genes are normally kept under control by a process called “DNA methylation,” which regulates gene activity. When methylation is lost, the genes can damage DNA and accelerate aging. An analysis of 864 dogs conducted as part of the Dog Aging Project, which ran for more than a year across the United States, showed that large dogs lose 35 percent more LINE1 methylation than small dogs.
University Blaise assessment
Blaise Mariner from Arizona State University noted that this is one of the clearest molecular markers aligning with the size-lifespan trade-off. The study also revealed that female large dogs may experience more LINE1 jumping; co-lead Brianah McCoy described this as “unexpected.”
A previous University of Arizona study had shown that the brains of large dogs do not age faster, and that the animals die without experiencing cognitive decline.
Noah Snyder details
It is not yet known whether LINE1 is a cause or a consequence of aging. Senior author Noah Snyder-Mackler said that dogs offer an extraordinary model for understanding aging and that the findings could lead to treatments that extend healthy lifespan in humans.