An international team of researchers has completed a genetic road map of the horse, an animal they found has a lot in common with humans. Scientists say the DNA blueprint could aid in the study of human diseases and improve breeding of horses.
|An unidentified rider takes Mastercraftsman for a run during Breeders' Cup races in Arcadia, Calif., 05 Nov 2009|
A consortium of researchers with the International Horse Genome Project drew the entire DNA map of the horse using genes from a Thoroughbred named Twinkle, with genetic contributions from Arabian and Quarter horses.
It turns out that horses - which were domesticated some 4-6,000 years ago - are remarkably similar at the cellular level to humans, according to veterinary scientist and project leader James Murray of the University of California at Davis.
"The horse itself is an extremely popular animal, in many cases a companion animal, but also a working animal throughout most of the world," he said. "And therefore it is of importance, just because of that, to try and then understand diseases in the horses that are caused by genetics, and [to] improve breeding. There are a variety of applications by having this information which can be advanced through research," he said.
There are some 2.7 billion genes in the chemical strands of DNA within each horse chromosome, which provide the hereditary code for various equine traits. Researchers say that while the horse genome is slightly smaller than that of the human, there are so many similarities in their DNA that horses and humans share more than 90 hereditary diseases.
Murray says that by understanding the genetics of horses, scientists can better understand the cause of many human diseases.
"I think that some of the exercise-related problems in terms of bones, joints, muscles; certainly in terms of breathing, cardiovascular; certainly some of the neurodegenerative diseases, all of these things are diseases which occur in the horse which often look very similar to things that occur in humans," he added.
Murray says he's aware of one horse disease that was first identified in the human genome.
"And it turns out that it's the same gene with a mutation that is causing the same disease in horses, and this is a periodic paralysis gene," said Murray.
Periodic paralysis is a rare genetic disorder in which muscles can become temporarily weak or paralyzed by a number of factors, including meals high in carbohydrates and salt.
Besides identifying the sources of heritable disease, experts say the horse genetic blueprint should help to improve the breeding of race horses, a $39 billion a year industry in the U.S. alone.
The horse sequencing project was led by a team of geneticists at the Broad Institute at MIT and Harvard University in Boston, and is published this week in the journal Science.