Genes behind dogs' diversity revealed

Washington, Jun 23: A Labrador is different in traits and behaviour from a retriever and likewise a Pug differs from a Chihuahua in many domains. But what causes this variability in size, shape, colour, coat length and behaviour amongst these most loved pets, is largely unexplained, until now. But now, scientists have developed a method to identify the genetic basis for this diversity that may have far-reaching benefits not only for dogs but also for their owners.

The new study reveals locations in a dog's DNA that contain genes that are believed to cause differences in body and skull shape, weight, fur colour and length - and possibly even behaviour, trainability and longevity. "This exciting breakthrough, made possible by working with leaders in canine genetics, is helping us piece together the canine genome puzzle which will ultimately translate into potential benefit for dogs and their owners. By applying this research approach, we may be able to decipher how genes contribute to physical or behavioural traits that affect many breeds," said study co-author Paul G. Jones, PhD, a Mars Veterinary genetics researcher at the Waltham Centre for Pet Nutrition.

Originally dogs have evolved from the wolf more than 15,000 years ago owing to selective breeding with physical and behavioural traits that were well suited to the needs or desires of their human owners, such as herding or hunting ability, coat colour and body and skull shape and size. This caused the massive variance seen among the more than 350 distinct breeds that make up today's dog population. And till date scientists wonder how and why the difference in physical and behavioural traits in dogs changed so rapidly from its wolf origins.

In the study, the researchers examined simple genetic markers known as Single Nucleotide Polymorphisms, or SNPs, to find places in the dog genome that correlate with breed traits. As many traits are "stereotyped" - or fixed within breeds - researchers could focus on these "hot spots" to see what specific genes are in the area that might contribute to differences in traits.

They used 13,000 dog DNA samples provided by Mars Veterinary, which holds one of the most comprehensive canine DNA banks in the world. Mars' DNA bank allowed the study to cover most of the American Kennel Club recognized breeds that span a wide variety of physical and behavioural traits and differences in longevity.

"With further refinement and additional data, this method could be used to tailor products that may benefit the health of pets. Pet owners and veterinarians may be able to develop better care regimes based on this knowledge. In addition, genetic information about behavioral traits, such as trainability and temperament, could also help veterinarians identify the most lifestyle-appropriate pet for an owner," said Jones.

The study may also have future implications for human health, as dogs suffer from many of the same diseases as humans do. The study is the cover story of the recent edition of the science journal Genetics.

ANI