Scientists in the UK have discovered small changes in the DNA of Labrador dogs, also found in humans, that could lead to more effective treatments for obesity.
Obesity is a major global health concern, affecting one in eight people worldwide, and 40-60% of pet dogs also develop obesity. While research has shown that obesity can be inherited, the specific genes that make some individuals more prone to weight gain and difficulty losing weight are still not fully understood.
In the study, researchers from the University of Cambridge, University of Birmingham and University of Liverpool collected saliva samples from more than 200 Labradors in order to isolate their DNA to measure body fat levels and score their greediness – Labradors are known to overeat more than other breeds.
Studying the genetic influences of obesity is challenging because diet and exercise habits vary widely. Dogs, on the other hand, live in more controlled environments, making it easier for scientists to separate genetic influences from lifestyle factors. Dogs of the same breed have more of their DNA in common, helping researchers identify genes linked to specific traits or diseases.
The study revealed multiple genes associated with obesity, with one gene in particular, DENND1B (which plays a role in a part of the brain that controls appetite and burning calories), having the strongest link. Labradors carrying a specific alteration in this gene had 7% more body fat than those without it.
Further research in humans found that alterations in the DENND1B gene are also linked to severe obesity.
Eleanor Raffan, lead researcher at Cambridge, explained: "This work shows how similar dogs are to humans genetically. Studying the dogs meant we had reason to focus on this particular gene, which has led to a big advance in understanding how our own brain controls our eating behaviour and energy use."