Dog genome unleashed

An international research team led by scientists at the Broad Institute of MIT and Harvard has decoded the DNA of the domestic dog and pinpointed millions of genetic differences that distinguish dog breeds. The study also includes the first comparative analysis to encompass three distinct mammalian genomes, revealing important DNA elements common among them. Such shared genetic signatures offer crucial insights into genome organization and function, particularly in humans. Their efforts, described in the Dec. 8, 2005 issue of Nature, shed light on the genetic similarities between dogs and humans as well as the genetic differences between dog breeds, and may guide future discoveries that improve the health of both species.

“Of the more than 5,500 mammals living today, dogs are arguably the most remarkable,” said senior author Eric Lander, director of the Broad Institute, professor of biology at MIT and of systems biology at Harvard Medical School, and a member of the Whitehead Institute for Biomedical Research. “The incredible physical and behavioral diversity of dogs – from chihuahuas to great danes – is encoded in their genomes. It can uniquely help us understand embryonic development, neurobiology, human disease and the basis of evolution.”

More than two years ago, the Nature paper’s authors embarked on a mission to assemble a complete map of the dog genome. In the first phase of the project they obtained high-quality DNA sequence from a female boxer named “Tasha,” covering nearly 99 percent of the dog’s genome. Because dogs sit at a key branch point in the evolutionary tree relative to humans, the dog genome sequence enabled researchers to make novel observations regarding the genetic similarities among mammals.