Posted on: Saturday, September 27, 2003

Fido's genes may be man's best friend

By Tim Friend
USA Today

Man's best friend is genetically more similar to his master than anyone might have imagined.

Scientists at The Institute for Genomic Research (TIGR) in Rockville, Md., report in yesterday's Science journal completion of a rough draft of the dog's "book of life." They found that 75 percent of the beast's genes have equivalents in the human.

Comparisons with the mouse and human genomes (the genetic makeup of a being) show that people are more similar to dogs than to mice.

The dog genome will advance the understanding of human diseases and provide information for veterinarians and people interested in variations of dog traits, TIGR's Ewen Kirkness says.

Scientists use dogs as models for more than 350 human diseases. When dogs are sick, they often have the same symptoms as humans with diseases ranging from arthritis to tumors, says William Murphy, a geneticist at the Laboratory of Genomic Diversity, National Cancer Institute. Murphy co-wrote a commentary on the article.

The subject of this project is a standard poodle named Shadow, a pampered "family" member of J. Craig Venter, TIGR founder and the scientist who used his own DNA when sequencing the human genome for private industry. Shadow is a well-known fixture roaming the executive suites at TIGR.

Nonprofit TIGR has led the field of genomic sequencing, starting with microbes and building up to rodents and, now, the dog.

The poodle project documents 80 percent of the dog's genes and shows that strings of mysterious genetic code between genes are identical in humans, dogs, mice and rats, Kirkness says. These regions may have been conserved over tens of millions of years of evolution and represent basic control mechanisms for life. The dog genome is smaller than that of humans — 2.1 billion letters of coding to our 2.9 billion letters.

Murphy says the research also is important because of the way it was conducted. Much debate has ensued over the value of rough drafts, known as "low coverage" genomes, vs. more complete versions. Rough drafts can be done more rapidly and for much less money. Some scientists argue that a rough draft would be as useless as a poorly edited manuscript.

"It bodes well for doing more species," says Murphy, who is seeking funding for a cat genome. "The key is that this shows there is value in doing low coverage."