Featured Research

from universities, journals, and other organizations

Analyzing the sheep genome for parasite resistance

Date:
October 18, 2011
Source:
USDA/Agricultural Research Service
Summary:
Genetic resistance to a parasitic nematode that infects sheep has been discovered by a team of agricultural scientists. 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.

ARS geneticist Tad Sonstegard, here preparing to load a genome analyzer, leads an international team that has found genetic resistance to a parasitic nematode that infects sheep and causes significant economic and production losses in Africa each year.
Credit: Photo by Stephen Ausmus

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).

Related Articles


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.

Read more about this research in the October 2011 issue of Agricultural Research magazine at: http://www.ars.usda.gov/is/AR/archive/oct11/food1011.htm


Story Source:

The above story is based on materials provided by USDA/Agricultural Research Service. The original article was written by Sandra Avant. Note: Materials may be edited for content and length.


Journal Reference:

  1. M. V. B. Silva, T. S. Sonstegard, O. Hanotte, J. M. Mugambi, J. F. Garcia, S. Nagda, J. P. Gibson, F. A. Iraqi, A. E. McClintock, S. J. Kemp, P. J. Boettcher, M. Malek, C. P. Van Tassell, R. L. Baker. Identification of quantitative trait loci affecting resistance to gastrointestinal parasites in a double backcross population of Red Maasai and Dorper sheep. Animal Genetics, 2011; DOI: 10.1111/j.1365-2052.2011.02202.x

Cite This Page:

USDA/Agricultural Research Service. "Analyzing the sheep genome for parasite resistance." ScienceDaily. ScienceDaily, 18 October 2011. <www.sciencedaily.com/releases/2011/10/111018131347.htm>.
USDA/Agricultural Research Service. (2011, October 18). Analyzing the sheep genome for parasite resistance. ScienceDaily. Retrieved November 28, 2014 from www.sciencedaily.com/releases/2011/10/111018131347.htm
USDA/Agricultural Research Service. "Analyzing the sheep genome for parasite resistance." ScienceDaily. www.sciencedaily.com/releases/2011/10/111018131347.htm (accessed November 28, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Friday, November 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

New Dinosaur Species Found in Museum Collection

New Dinosaur Species Found in Museum Collection

Reuters - Innovations Video Online (Nov. 27, 2014) A British palaeontologist has discovered a new species of dinosaur while studying fossils in a Canadian museum. Pentaceratops aquilonius was related to Triceratops and lived at the end of the Cretaceous Period, around 75 million years ago. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Classic Hollywood Memorabilia Goes Under the Hammer

Classic Hollywood Memorabilia Goes Under the Hammer

Reuters - Entertainment Video Online (Nov. 26, 2014) The iconic piano from "Casablanca" and the Cowardly Lion suit from "The Wizard of Oz" fetch millions at auction. Sara Hemrajani reports. Video provided by Reuters
Powered by NewsLook.com
Pet Dogs to Be Used in Anti-Ageing Trial

Pet Dogs to Be Used in Anti-Ageing Trial

Reuters - Innovations Video Online (Nov. 26, 2014) Researchers in the United States are preparing to discover whether a drug commonly used in human organ transplants can extend the lifespan and health quality of pet dogs. Video provided by Reuters
Powered by NewsLook.com
From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

Newsy (Nov. 25, 2014) The US FDA is announcing new calorie rules on Tuesday that will require everywhere from theaters to vending machines to include calorie counts. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins