On Dogs and Research

Photo credit: National Geographic News

Since the first family just got a new dog, we thought it would be interesting to share some information about dogs, how different breeds evolve, and how man’s best friend has more in common with us than we might suspect. Today’s guest bloggers – and genetics experts - Tyrone Spady and Pascale Quignon are postdoctoral fellows at the National Institutes of Health.

***

The domestic dog (read: friendly, furry pet) arguably shows more variation than any other species of land animal. From the smallest Chihuahua to the tallest Great Dane, and from the long-haired Afghan hound to the short-haired boxer, all are members of the species Canis familiaris. Their tails can be curly, straight, or even kinked. Their ears can be long and droopy, short and up-right, or anywhere in between. And with 224 dog breeds recognized by the American Kennel Club (AKC), choosing the breed of the First dog was bound to be difficult process for the Obamas, who like many families across the United States, were confronted with the seemingly endless variety dogs.

Although the extreme diversity of dogs may make it difficult for indecisive would-be dog owners*, from a scientific perspective it creates an incredible opportunity to understand the genetic basis of morphology (size and shape), behavior, and disease susceptibility.

New Voices blogger Heather with the family Collie puppy, Baggins, in Dec. 2008.

Dogs were developed to herd, guard, track, point, chase, flush, retrieve, pull and, of course, cuddle. By the mid 19th century, dog fanciers had formalized the “breed” concept and developed written breed standards of appearance and sometimes behavior. To be a member of a breed according to the AKC, both a dog’s parents must be registered members of the breed. When mated, members of a breed must reliably pass on uniform, breed-defining characters. To create new breeds, dogs of different varieties may be crossed or members of an existing breed may be subdivided based on key defining characters, such as size.

Breeds therefore represent closed, genetically similar populations of animals that are alike in appearance and behavior. Because breeds have a genetic base, scientists can look at traits and try to identify the specific genes that make poodles different from St. Bernards. Scientists studying the Portuguese water dog (the breed the Obama’s chose) have identified a gene that helps make small dogs small.

Friend of New Voices Kate, a Basenji shepherd, on a trail in Alabama last week.

As man’s best friend, dogs share our environment and many diseases that affect us, including cancers, cataracts, and neurological disorders. Since dogs and humans share most of the same genes, understanding more about how dog genes control growth and development will enhance our understanding of basic human biology.

A shining example of how discoveries in the dog reveal new targets for human therapies is illustrated by studies of narcolepsy in the Doberman pinscher. Studies on Dobermans revealed a biochemical pathway involved in both dog and most human narcolepsy. As a result, several new treatments are being developed. Identifying the function of genes in the dog, therefore, represents an invaluable opportunity to develop knowledge that could lead to improved treatments of human illness.

Tyrone Spady, PhD and Pascale Quignon, PhD are both postdoctoral fellows in the Cancer Genetic branch of the National Human Genome Research Institute at the NIH.

***

FlyGal's dog Selva

We know that’s just an overview of dog genetics and the basics of breeds, so if you have other questions, feel free to post them up. We’ll be working with our expert guest bloggers and will do a follow up post to answer any questions you might have. Also, you may have noticed the fun photos of the New Voices dogs throughout the post. Share your photos with us (please include the name of your adorable pooch and breed if known) and we’ll post them along with the answers to readers questions!


*If you’re looking for a furry friend to add to your family, there are a number of great adoption agencies across the U.S. that will help match your needs and desires with the perfect pet. For more information on matching, check out the Washington Area Rescue League's Meet Your Match.

[To share pictures, leave a link in the comments or email photos to: hbenson at researchamerica.org]