2003-09-26 11:25:20 -- Humans share three-quarters of their genes with man's best friend, according to the first genetic blueprint of the domestic dog.

Scientists in the United States found the genetic material shared by dogs and humans amounts to more than 650 million of the chemical units, called base pairs, that make up DNA.

Analysis showed that for 75% of known human genes - lengths of DNA that provide the building instructions for proteins - there was an equivalent dog gene. A total of 18,473 of the known 24,567 human genes had a canine version.

The researchers, who included gene mapping pioneer Dr Craig Venter, used a male standard poodle as their DNA source. They say their dog genome, published in the journal Science, is more of an 80% complete rough sketch than a detailed map.

But although fragments were missing from many of the DNA sequences, the scientists say they've uncovered data which may be useful in identifying genes causing disease in both dogs and humans.

Dr Venter, president of The Centre for Advancement of Genomics in Rockville, Maryland, USA, said: "In little more than a decade genomics has advanced greatly and we now have approximately 150 complete genomes, including the human, mouse and fruit fly, in the public domain."

One major and not unexpected difference between the dog and human genomes lies in their noses. The dog genome encodes for a much greater variety of smell sense proteins than does the human.

Dogs have been domesticated for more than 10,000 years. Knowledge of their medical problems is second only to that of humans, and dogs succumb to 360 genetic diseases with human counterparts.

The dog genome is smaller than ours, consisting of 2.4 billion base pairs compared with 2.9 billion for a human. Dogs also have 78 chromosomes, the bundles of DNA found in the nucleus of every cell, whereas humans have 46.

Both The Centre for Advancement of Genomics and the Institute for Genomic Research took part in the project.


Story filed: 06:41 Friday 26th September 2003