Breakthrough Made in Cure For Equine Skin Disease
Equestrian News Release
The elimination of a debilitating, degenerative skin disease in
horses is now possible thanks to the recent identification of a gene
mutation and development of a new diagnostic test by researchers at
the University of California, Davis.
Findings from the study on the genetic cause of Hereditary Equine
Regional Dermal Asthenia (HERDA) which primarily affects the
American quarter horse breed, were reported online May 8 in the
scientific journal Genomics by veterinary geneticist Danika Bannasch
and colleagues at the UC Davis School of Veterinary Medicine. A
patent on the newly developed test is pending.
"Identification of the gene enabled us to develop a DNA screening
test to help horse breeders avoid producing horses with this
disease," Bannasch said. "Equally important, the test should prevent
the unnecessary destruction of young horses that actually have less
serious skin irregularities, which can be mistaken for the early
stages of HERDA."
This research represents the first time a scan of the whole horse
genome has been used to identify a novel disease gene in the horse.
These findings were presented to the horse genomics community at the
Plant and Animal Genome XV Conference in January by Rob Tryon, the
graduate student working on the project. Stephen White, a professor
of veterinary dermatology at UC Davis, led the clinical
investigations of HERDA.
About the disease
HERDA causes skin along the saddle area of the horse's back to
stretch and tear easily, making the horse unfit for riding.
Researchers suspect that the disease may be related to a deficiency
in the horse's wound healing process or a malfunction in its normal
inflammatory response system. An earlier study of affected horses by
the UC Davis group demonstrated that the disease cannot be
definitively diagnosed by skin biopsy. Foals affected by the disease
rarely show symptoms at birth, and most cases are not diagnosed until
the horse is about two years old and being broke to ride.
Previous work by the UC Davis group showed that the disease has an
autosomal recessive mode of inheritance and carriers show no signs of
the disease. Breeders may never know that their horses are carriers
of the disease because they usually sell their affected foals before
the horses show symptoms. Since there is no available treatment, most
horses diagnosed with the disease are euthanized because they cannot
be ridden and are unsuitable for future breeding.
Identifying the gene mutation
The UC Davis team members began their search for the mutation with
the entire complement of horse genes, totaling about 25,000 genes.
They were able to narrow the location to chromosome 1, the largest of
the horse chromosomes, by identifying the section of the genome that
was identical in horses affected by the disease. From there, they
were able to zero in on a group of 20 genes in this region by
comparing related regions in the genomes of humans, chimpanzees,
mice, dogs and cows. The team performed a sequence analysis of those
genes, and then identified the mutation.
Screening for this genetic mutation among the study's control group
of unaffected horses suggests that 3.5 percent of American quarter
horses are carriers. Although carriers do not develop symptoms, they
can produce affected foals if bred to other carriers.
Funding for the research was provided by the American Quarter Horse
Foundation and the Center for Equine Health at the UC Davis School of
Veterinary Medicine.
Courtesy: The HorseTV Channel News, http://www.horsetv.com
Reader Comments
Be the first to submit a comment on this article!
Submit your comments
Link to this article
---------------------- It's easy! Just copy code below and paste into your webpage --------------------
<a href="http://www.equestrianmag.com/article/cure-for-equine-skin-disease-5-07.html">Breakthrough Made in Cure For Equine Skin Disease</a> ~ EquestrianMag.com
----------------------------------------------------------------------------------------------------------------------------------
Your link will appear like this:
Breakthrough Made in Cure For Equine Skin Disease ~ EquestrianMag.com
|
