(Press-News.org) Mapping the ancestry of sheep over the past 11,000 years has revealed that our woolly friends are stars among domestic animals, boasting vast genetic diversity and substantial prospects for continued breeding to further boost wool and food production for a rising world population.
An international research team has provided an unprecedented in-depth view of the genetic history of sheep, one of the world's most important livestock species. The study, published February 7 in the online, open-access journal PLoS Biology, maps out how humans have moulded sheep to suit diverse environments and to enhance the specialised production of meat, wool and milk.
The study identified particular regions of the sheep genome that appear to have changed rapidly in response to selection for genes controlling traits such as coat colour, body size, reproduction and, especially, the lack of horns – one of the earliest goals of selective breeding.
Detailing sheep domestication and migration patterns across the globe, it also supports and adds to the current knowledge of human movements throughout history.
The team traced the relatedness between nearly 3,000 sheep by comparing 50,000 DNA sites across the genome, and pinpointed the genetic consequences of domestication and subsequent division of sheep into hundreds of breeds, according to lead author Dr James Kijas from Australia's national science agency, CSIRO.
"Our detailed gene map is telling us that sheep breeds have been formed in a 'fluid' way that makes them different from other species of domestic animals. Frequent mating and strong gene flow between animals of different breeds has ensured that most modern sheep breeds have maintained high levels of genetic diversity, in contrast to some breeds of dogs and cattle that generally have higher levels of inbreeding," Dr Kijas says.
"This high level of genetic diversity means that sheep breeders can continue to expect strong improvements in important production traits – improvements that could play a part in feeding the growing number of people in the world, with an increasing demand for animal protein."
"The technology that we have used in this study is helping to identify genes that control economically important traits, and to track down genetic variants that cause diseases. This may ultimately help producers to intensify or remove certain traits through targeted breeding practices."
The extensive DNA sampling that underpins the research, encompassing 74 sheep breeds from around the world, will provide a touchstone for livestock research for years to come, including studies of genetic diversity to better manage the conservation of threatened breeds.
###The research was facilitated and coordinated through the International Sheep Genomics Consortium.
Funding: Funding for this work was collected through the International Sheep Genomics Consortium. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests exist.
Citation: Kijas JW, Lenstra JA, Hayes B, Boitard S, Porto Neto LR, et al. (2012) Genome-Wide Analysis of the World's Sheep Breeds Reveals High Levels of Historic
Mixture and Strong Recent Selection. PLoS Biol 10(2): e1001258. doi:10.1371/journal.pbio.1001258
CONTACT:
James Kijas
CSIRO, Australia
Livestock Industries
306 Carmody Rd
Brisbane, 4067
AUSTRALIA
Tel: 61-7-32142442
James.Kijas@csiro.au
Disclaimer:
This press release refers to an upcoming article in PLoS Biology. The release is provided by journal staff, or by the article authors and/or their institutions. Any opinions expressed in this release or article are the personal views of the contributors, and do not necessarily represent the views or policies of PLoS. PLoS expressly disclaims any and all warranties and liability in connection with the information found in the releases and articles and your use of such information.
About PLoS Biology:
PLoS Biology is an open-access, peer-reviewed journal published by the Public Library of Science featuring research articles of exceptional significance, originality, and relevance in all areas of biology. Copyright on all works is retained by the authors. The Public Library of Science uses the Creative Commons Attribution License.
About the Public Library of Science:
The Public Library of Science (PLoS) is a non-profit organization of scientists and physicians committed to making the world's scientific and medical literature a freely available public resource. For more information, visit http://www.plos.org.
Not the black sheep of domestic animals
2012-02-08
ELSE PRESS RELEASES FROM THIS DATE:
New guidelines suggest DVT prophylaxis not appropriate for all patients
2012-02-08
New evidence-based guidelines from the American College of Chest Physicians (ACCP) recommend considering individual patients' risk of thrombosis when deciding for or against the use of preventive therapies for deep vein thrombosis (DVT) and venous thromboembolism (VTE). Specifically, the Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines, published in the February issue of the journal CHEST, focus on risk stratification of patients, suggesting clinicians should consider a patient's ...
Brain mechanisms link foods to rising obesity rates
2012-02-08
CINCINNATI—An editorial authored by University of Cincinnati (UC) diabetes researchers to be published in the Feb. 7, 2012, issue of the journal Cell Metabolism sheds light on the biological factors contributing to rising rates of obesity and discusses strategies to reduce body weight.
According to the U.S. Centers for Disease Control, about one-third of U.S. adults are obese, a number that continues to climb.
"While we don't usually think of it this way, body weight is regulated. How much we weigh is influenced by a number of biological systems, and this is part ...
Metabolic profiles essential for personalizing cancer therapy
2012-02-08
One way to tackle a tumor is to take aim at the metabolic reactions that fuel their growth. But a report in the February Cell Metabolism, a Cell Press Publication, shows that one metabolism-targeted cancer therapy will not fit all. That means that metabolic profiling will be essential for defining each cancer and choosing the best treatment accordingly, the researchers say.
The evidence comes from studies in mice showing that tumors' metabolic profiles vary based on the genes underlying a particular cancer and on the tissue of origin.
"Cancer research is dominated now ...
Transmission of Clostridium difficile in hospitals may not be through contact with infected patients
2012-02-08
Contrary to current convention by which infection with the organism Clostridium difficile is regarded as an infection that is acquired by contact with symptomatic patients known to be infected with C. difficile, these may account for only a minority of new cases of the infection. These findings are important as they indicate that C. difficile infection, which can be fatal especially in older people, may not be effectively controlled by current hospital infection strategies.
In a study led by Professor Tim Peto of the John Radcliffe Hospital in Oxford, UK, and published ...
Mild cognitive impairment is associated with disability and neuropsychiatric symptoms
2012-02-08
In low- and middle-income countries, mild cognitive impairment—an intermediate state between normal signs of cognitive aging, such as becoming increasingly forgetful, and dementia, which may or may not progress—is consistently associated with higher disability and with neuropsychiatric symptoms but not with most socio-demographic factors, according to a large study published in this week's PLoS Medicine.
The established 10/66 Dementia Research Group interviewed approximately 15 000 people over 65 years of age who did not have dementia in eight low- and middle-incomes ...
Parcel2Go Hails UK's Entrepreneurial Spirit
2012-02-08
Online parcel delivery specialist Parcel2Go has applauded the drive and will to succeed of the thousands of people across the UK who decide to start their own businesses. In the face of rising unemployment across Britain and the threat of a double-dip recession, entrepreneurs of all kinds are grasping the opportunity to take control of their own future.
Figures released last month by the Office for National Statistics showed the number of people registered as self-employed in the UK increased by 101,000 during the three months to November 2011, representing a 3.5 per ...
More focus on men needed in HIV prevention
2012-02-08
Edward Mills of the University of Ottawa, Canada and colleagues argue in this week's PLoS Medicine that the HIV/AIDS response in Africa needs a more balanced approach to gender, so that both men and women are involved in HIV treatment and prevention. Traditionally, targeted efforts at reducing the impact of the HIV epidemic have focused on women and children while men have received considerably less attention.
The authors say: "The epidemiological evidence is accumulating, and indicates that males in sub-Saharan Africa are not accessing HIV services as often as their ...
Childhood Choice...Bank Account for Life?
2012-02-08
The average person in the UK has had their main bank account for more than 20 years, according to new research from Halifax.
In figures that demonstrate the average person's reluctance to move bank account providers, the bank found that:
- 1 in 10 adults still use the account that they opened between the ages of 1 and 15 years old as their main account today
- A third of adults opened their main current account between the ages of 16-24
- Over a quarter of people (26%) have held their current main account for more than 26 years
Parent and student account define ...
Administration of meningococcal vaccine with other routine infant vaccines appears effective
2012-02-08
CHICAGO – Administration of routine infant immunizations with a vaccine for serogroup B Neisseria meningitidis, a bacterium that is a cause of serious disease such as sepsis and meningitis, was effective against meningococcal strains and produced minimal interference with the response to the routine vaccinations, according to a study in the February 8 issue of JAMA.
Certain serogroup B Neisseria meningitidis (MenB) vaccines proved effective in clinical trials and controlled a clonal MenB outbreak in New Zealand; however, the high strain specificity of these vaccines ...
Risk of death from breast cancer higher among older patients
2012-02-08
CHICAGO – Among postmenopausal women with hormone receptor-positive breast cancer, increasing age was associated with a higher risk of death from breast cancer, according to a study in the February 8 issue of JAMA.
"Breast cancer is the leading contributor to cancer incidence and cancer mortality in women worldwide, with 1,383,500 new cases in 2008. In the United States in 2008, 41 percent of these women were aged 65 years or older at diagnosis. Because breast cancer incidence increases with increasing age, changing demographics and continuously increasing life expectancy ...