Research Closes in on Goat Scrapie
By Jan Suszkiw
April 3, 2009
Goats are tough, spirited animals, but they're no match for scrapie, a
form of transmissible spongiform encephalopathy. Now, with a "helping hand"
from science, the animals' plight could take a turn for the better.
Toward that end, Agricultural
Research Service (ARS) scientists and their collaborators have developed a
live-animal test to detect scrapie in goats. Called the rectal mucosa biopsy
test (RMBT) or rectal biopsy, the new method involves snipping a tiny piece of
lymphoid tissue from the lining of an afflicted animal's rectum. A dab of local
anesthetic eases the animal's discomfort, notes microbiologist
O'Rourke with the
Animal Diseases Research Unit in Pullman, Wash.
Lymphoid tissue is used because it collects malformed proteins called
prions, which are thought to cause scrapie, adds O'Rourke. She's a member of a
scrapie research team that includes Washington
State University, Colorado State
University, the Animal and Plant
Health Inspection Service (APHIS), the National Park Service and the
Advantages of using the rectal biopsy test method include speed,
easier methodology and its generation of a high number of repeat samples from
On a related front, ARS Pullman geneticist
White is leading studies to characterize the prion protein gene of goats
and identify differences between individual animals and breeds harboring the
gene. His team has so far examined the sequences and distribution of
allelesalternative forms of genesfrom 446 goats representing 10
breeds, including Alpine, Angora, Boer and Nubian.
The ARS Pullman lab also is collaborating with APHIS to formulate a
strategy aimed at helping the U.S. goat industry eliminate scrapie from its
herd, which numbers four million head. Hardships imposed by scrapie on
America's goat and sheep producers include the physical loss of animals, costs
of disposal of carcasses and offal, trade restrictions and diminished domestic
and international markets for breeding stock, semen and embryos.
about this research in the April 2009 issue of Agricultural Research
ARS is the principal intramural scientific research agency of the
U.S. Department of Agriculture.