(Press-News.org) Genetic resistance to a parasitic nematode that infects sheep has been discovered by a team of scientists with the U.S. Department of Agriculture (USDA) and the International Livestock Research Institute (ILRI).
The researchers are the first to detect quantitative trait loci (QTL), genetic locations on chromosomes, for resistance to gastrointestinal nematode parasites in a double-backcross population derived from African native sheep. The parasites, common in tropical regions, cause significant economic and production losses in Africa each year. Sheep infected with parasites suffer from diarrhea, anemia, weight loss and sometimes death.
Geneticist Tad Sonstegard at the Agricultural Research Service (ARS) Henry A. Wallace Beltsville Agricultural Research Center in Beltsville, Md., and researchers at ILRI in Kenya hope to identify genes that increase tolerance to parasites and improve production of grazing animals. ARS is USDA's chief intramural scientific research agency, and this research supports USDA's priority of promoting international food security.
In one study, researchers mapped the regions of the genome that control resistance to gastrointestinal nematode parasites in a sheep population bred by ILRI. Hybrid rams were produced by mating a Red Maasai, which is tolerant to gastrointestinal parasites, to a Dorper, a breed that is more susceptible to the parasite. Several of the hybrid ram offspring were then bred to either Red Maasai or Dorper ewes to complete the backcross.
Scientists genotyped 20 percent of the backcross progeny to map QTL that affect parasite-resistance traits. Blood packed-cell volume and fecal egg count-indicators of parasites-were collected for three months from more than 1,060 lambs that grazed on parasite-infected pastures. Scientists selected lambs for genotyping based on parasite indicators. They detected significant QTL for average fecal egg count and packed-cell volume on chromosomes 3, 6, 14, and 22.
Future studies will focus on genotyping the same animals using the OvineSNP50, according to Sonstegard. The OvineSNP50 is a powerful tool that can examine more than 50,000 locations in the genome.
Findings from this research were published online in Animal Genetics in May 2011.
INFORMATION:
Read more about this research in the October 2011 issue of Agricultural Research magazine.
http://www.ars.usda.gov/is/AR/archive/oct11/food1011.htm
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Evolution of a Stream: Plants and sea-life claim new territory as glaciers retreat in Glacier Bay, Alaska
As tidewater glaciers beat a hasty retreat up Glacier Bay in southeast Alaska, they uncover rocky, barren landscapes and feed cold lakes and streams — new habitat for life's hardy explorers. In the October issue of Ecology, researchers from the Universities of Birmingham, Roehampton and Leeds describe the evolution and assembly of a stream ecosystem in newly de-glaciated terrain, from early insect and crustacean invaders to the arrival of migrating salmon.
Sampling ...
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PATH Malaria Vaccine Initiative
First results from Phase 3 trial show malaria vaccine candidate reduces the risk of malaria
First results from ongoing Phase III trial show malaria vaccine candidate, RTS,S* reduces the risk of malaria by half in African children aged 5 to 17 months
Seattle, 18 October 2011 — First results from a large-scale Phase III trial of RTS,S, published online today in the New England Journal of Medicine ...
The custom framing industry has not yet made its mark on the Internet due to the fact that custom frames are not simple products. Customizable products have just recently begun to penetrate into the world of e-commerce due to advancements in development platforms and connection speeds. Frames4Less.com, a Menache Ecommerce company, aims to bring custom frames within reach of the general population using a fancy new website equipped with a state of the art Custom Framing Interface.
Custom picture frames are expensive and time consuming to order, many don't resort to ...
BLOOMINGTON, Ind. -- A new study by researchers at Indiana University and George Mason University found the sexual repertoire of gay men surprisingly diverse, suggesting that a broader, less disease-focused perspective might be warranted by public health and medical practitioners in addressing the sexual health of gay and bisexual men.
The study, published online ahead of print in the Journal of Sexual Medicine, tapped the largest sample of its kind in the United States to examine the sexual behaviors of gay and bisexual men. In collaboration with the OLB Research Institute ...
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At almost 200 square miles, Coiba Island is the largest offshore island along ...
PHILADELPHIA — An experimental vaccine developed by researchers at the University of Pennsylvania's schools of Medicine and Veterinary Medicine is the first veterinary cancer vaccine of its kind that shows an increase in survival time for dogs with spontaneous non-Hodgkin's lymphoma. The work shows for the first time the feasibility and therapeutic efficacy of this alternative cell-based vaccine, which could be employed in the treatment of a number of different cancer types.
The research was conducted by Nicola Mason, assistant professor of medicine at Penn Vet; Robert ...
On October 13, with little fanfare, Congressman Jeff Fortenberry (NE-1) introduced the Veterans Entrepreneurial Transition (VET) Act of 2011, a landmark new GI Bill that would allow veterans to use their already budgeted educational benefits earned under existing GI Bills, to start up new small businesses.
The VET Act (H.R. 3167) is a GI Bill aimed at addressing the unacceptably high veteran unemployment rate, as well as to help quickly re-build a new generation of veteran-owned small business enterprises across America as the backbone of new job creation.
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Why did the approval ratings of President George W. Bush— who was perceived as indecisive before September 11, 2001—soar over 90 percent after the terrorist attacks? Because Americans were acutely aware of their own deaths. That is one lesson from the psychological literature on "mortality salience" reviewed in a new article called "The Politics of Mortal Terror." The paper, by psychologists Florette Cohen of the City University of New York's College of Staten Island and Sheldon Solomon of Skidmore College, appears in October's Current Directions in Psychological Science, ...
WINSTON-SALEM, N.C. – Oct. 18, 2011 – Family matters, especially when it comes to African-Americans and living kidney donation. In a study conducted at Wake Forest Baptist Medical Center, researchers found that African-Americans donate almost exclusively to family members for living kidney transplants, as compared to Caucasians.
The retrospective study, published in the September/October online issue of the journal Clinical Transplantation, compared medical records of all former successful kidney donors at Wake Forest Baptist between Jan. 1, 1991, and Dec. 31, 2009. The ...
A team of Canadian researchers has sequenced the genome of Cannabis sativa, the plant that produces both industrial hemp and marijuana, and in the process revealed the genetic changes that led to the plant's drug-producing properties.
Jon Page is a plant biochemist and adjunct professor of biology at the University of Saskatchewan. He explains that a simple genetic switch is likely responsible for the production of THCA, or tetrahydrocannabinolic acid, the precursor of the active ingredient in marijuana.
"The transcriptome analysis showed that the THCA synthase gene, ...
