U. team collars genetic facts in work with dogs

The Portuguese water dog is a curly coated, water-loving dog described by breeders as "lively but sensible." It is also a pure-bred, which makes it an ideal subject for genetic study.

The results of that study — by K. Gordon Lark, distinguished professor emeritus of biology, and his colleagues at the University of Utah — were announced Wednesday in a dog genetics blitz that included the publication of the first virtually complete decoding of dog DNA.

Dogs, the research shows, are also man's best friends for researching the genetics of human diseases and behavior, from diabetes to aggression. The research will also benefit canines, providing clues that can improve breeds, Lark said.

"It's kind of a happy trade-off."

The genome announcement was made at a dog show in Boston and was published in today's issue of the journal Nature.

"Outside of a dog, a book is man's best friend. Inside of a dog, it's too dark to read," quipped Dr. Francis Collins, director of the National Human Genome Research Institute, quoting the late comic Groucho Marx. "We're here to unveil the book of the dog." The research was overseen by the Broad Institute of Harvard and MIT.

Along with the mouse, rat and several insect species, "the dog is now set to take its rightful place as a valued system for genetic studies," according to Dr. Elaine Ostrander and Dr. Francis Galibert, in the foreword to the book "The Dog and Its Genome," published Wednesday. Lark's work on Portuguese water dogs is featured in both this book and a special dog section in today's issue of the journal Genome Research.

As a species — C. familiaris — the dog shares more than 300 genetic diseases with man, including seizures, cancers, autoimmune diseases, heart disease and blindness. Studying dogs may also teach humans about the genetics of their own skeletal development. The Utah group, for example, has found chromosomal indicators that affect hip laxity and osteoarthritis, shedding light on osteopathology in humans. Dog genetics can also provide clues to complex behaviors such as anxiety and aggression, Lark said.

Variation among dog breeds, including their size, shape and behavior — think chihuahua and St. Bernard — is greater than for any other animal, which makes dogs a model organism to tease out aspects related to genes and those caused by environmental factors. The fact that dogs reproduce quickly and have large litters also helps.