Iberian with owner


Horse Genome Project


International Equine Genome Mapping Workshop
The 8th Dorothy Russell Havemeyer Foundation International Equine Genome Mapping Workshop took place near Newmarket, UK from July 22 to 25, 2009...[more]

Writers at the Louisville Courier Journal recently won the 2008 Media Eclipse Award for journalism based on an article about Thoroughbred racing and break-downs. They published a 3 part story, including genetics, track surfaces and medications. In connection with the genetics section they interviewed several members of the Horse Genome Project. See the accompanying links for the full stories on the 2008 Media Eclipse Award and the article itself.

Courier-Journal Web site wins award for horse project
Genetics may hold key to Injury-prone horses
[December 2008]

The first draft of the horse genome sequence was recently completed and deposited...
[JAVMA News, April 2007]

Data on Equine Genome Freely Available to Researchers Worldwide
[NIH News, February 2007]

The first genome map of a horse is complete, providing scientists with new tools for investigating equine disease. [ April 2006]



How will genomics change horsemanship?

Some horsemen may worry that once the horse genome is sequenced, all the mystery and magic will be gone from horse breeding and ownership.  Colorful characters around a racetrack may be replaced by colorless scientists with computer printouts and test tubes.  Fear not.  The study of the horse genome is more like studying the weather than inventing a sports car.  Consider the following. All our research on the weather has shown we can experience a sunny day in Florida knowing that a hurricane will arrive in two days, but we cannot change the hurricane.  Still the knowledge allows us to make choices; when the hurricane approaches we can abandon town or we can shore up our foundations.  Successful use of genomic tools will help the horse breeders, veterinarians and horse owners to do better what they already do… anticipate problems, predict outcomes and enjoy the unique interaction between horses and people. 

Even before the horse genome was sequenced, DNA tests were developed for inherited diseases of horses as well as many coat color patterns.  So far breeders can test horses and determine the chances of transmitting genes for the following disease traits to their offspring:  hyperkalemic periodic paralysis of Quarter Horses (HYPP), severe combined immunodeficiency disease of Arabian horses (SCID), overo lethal white foal disease of paint horses (OLWFD), junctional epidermolysis bullosa of Belgian horses (JEB), glycogen branching enzyme deficiency of draft horses (GBED), and  hereditary equine regional dermal asthenia of Quarter horses (HERDA).  In the near future we may have the genes for other simple hereditary diseases identified.   Color genetics has also improved from the availability of these new tools.  Genetic tests are available for black/chestnut (MC1R), bay/black (ASIP), cream dilution (MATP), Frame overo (OLWFD), sabino 1 (KIT) and tobiano (KIT).   Although the gene has not yet been identified for these colors, mapping studies localized genes for gray, appaloosa, dominant white and roan.

Horses are athletic working animals selected for health and performance for thousands of years.  Consequently, horses have few purely genetic diseases.  The real benefit of genomics for horses will be to understand complex diseases that have frustrated horse owners and veterinarians since the time of domestication. These conditions affect the musculoskeletal system (osteoarthritis, tying up, contracted foals), joints and bones (osteocondrosis, navicular disease, laminitis, congenital limb deformity), allergic diseases, respiratory diseases (recurrent airway obstruction, heaves, exercise induced pulmonary hemorrhage) and infectious diseases (vaccine development for viruses and bacteria). 

Why do these problems exist for a species highly selected for health and performance?  We don’t know. It may be related to the complex interplay of genes and our social needs.  Sometimes it can be inadvertent.  HYPP is caused by a single change in a DNA molecule that disrupts potassium metabolism in muscle cells.  The muscles undergo spontaneous and aberrant contractions, similar to isometric exercises, resulting in a muscular appearance.  Unfortunately, such horses may collapse under the stress of muscular exertion. We expect that selection for large muscling in Quarter horses led to selection for the HYPP gene.  Likewise, selection for small size in miniature horses may inadvertently lead to selection for genes causing dwarfism.   The point is to understand the interplay of genes and management, then allow breeders and horse owners to do what they have always done, make informed choices. 

The horse genome sequence is going to accelerate research and save hundreds of thousands of research dollars.  Before now, many scientists would begin projects by spending months cloning and sequencing DNA for the gene of interest.  When the horse gene was entirely unknown, scientists would use information from humans, mice or rats to provide a “best guess” starting point.  Now, with the whole genome sequence, anyone with access to the internet can circumvent this tedious spadework.  The availability of this information means that one does not need to be a molecular geneticist to use the information.  We anticipate research projects by a wide range of scientists, worldwide during the next couple of years.

(excerpt from ECRG press release)

running horses

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