Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Researchers seek to clone ’mad cow disease’ resistant cattle strain


Scientists in the Virginia-Maryland Regional College of Veterinary Medicine (VMRCVM) at Virginia Tech are trying to clone cattle that are genetically incapable of developing "Mad Cow Disease."

As federal and state government officials grapple with strategies to limit the economic and health risks associated with the troublesome discovery of the nation’s first case of Bovine Spongiform Encephalopathy (BSE) – or "Mad Cow Disease"-- Will Eyestone, research associate professor in Large Animal Clinical Sciences, and Bill Huckle, associate professor of biomedical science, are conducting important research with the little understood molecules believed to cause the deadly brain-wasting disease.

Eyestone, a molecular reproductive biologist who was senior research scientist for PPL Therapeutics, the organization that cloned Dolly the sheep, now heads the VMRCVM’s transgenic animal research program.

Most people think of disease as being caused by infectious organisms like bacteria, viruses, rickettsia, protozoa or fungi, explains Eyestone. Those microorganisms reproduce themselves to cause disease in fairly conventional ways, either inside a cell or elsewhere in the body.

But prions behave very differently than these more common disease-causing organisms, explains Eyestone. Prions are actually a form of protein that naturally occur in all mammals, though scientists remain uncertain about the exact purpose they serve in advanced mammals like humans. Transmissible spongiform encephalopathies like BSE and new variant Creutzfeldt-Jacob Disease (vCJD), the human form of the disease, are believed to occur when the non-pathogenic prions that normally reside in mammalian nervous systems are converted into pathogenic forms.

Proteins, the building blocks of metabolic processes, are long chains of amino acids that fold in upon themselves in predictable patterns and shapes that result from the bio-electrical relationships that exist between individual molecules, according to Eyestone. Proteins normally "fold" in only one way. But when the "normal" prions are infected by pathogenic prions, they begin to "fold" in another way that leads to disease.

In the case of BSE and vCJD, pathogenic prions introduced from contaminated food sources interact with normal prions in the body and transform them into the lethal agents that eventually create the "Swiss cheese-like" lesions in the brain that cause the devastating neurological symptoms of the disease.

The pathogenic prions that are ingested by cattle in contaminated feed do not seem to be affected by the normal enzymatic activity of the digestion process, explains Eyestone. The prions pass through the wall of the gut and are subsequently absorbed by innervated lymphatic tissues, where they eventually accumulate in the nerves, and then migrate to the spinal cord and brain. The process takes years, Eyestone says, which accounts for the five to seven year incubation period that characterizes both the animal and human forms of the disorder.

While scientists don’t know how to stop the pathogenic process once it gets underway, some, like Eyestone and Huckle, are interested in creating an animal that lacks the genomic architecture to code for the production of normal prions.

"In order to be susceptible to prion disease, the individual has to be able to express the prion," says Eyestone, who is using the same somatic cell transfer technology to clone a cow without normal prions that PPL used to create Dolly the sheep and Mr. Jefferson, the first cloned calf.

Basically, the process involves taking somatic cells harvested from an animal, and replacing the nucleus of that cell with the nucleus of another cell that possesses the desired genetic characteristics, and then implanting that embryo into the animal for a normal gestational development period.

"We know that if you knock out these prion proteins in laboratory mice that there is no apparent negative effect," said Eyestone. "We know that this prion does not appear to be required for normal functions of life. But the mouse has not been that informative to us and we are hoping that the cow will be more so."

The research is funded by the National Institutes of Health. The core objective of the NIH grant is to produce a cow that is genetically incapable of producing prions, and then determine whether or not the viability and function of the animal has been affected by the lack of the prion. Once the cow is cloned in late 2004, the researchers will conduct a number of behavioral and physiological evaluations of the animal.

If efforts to produce a normally functioning cow that lacks the genetic ability to code for the production of prions are successful, the researchers may have identified a strategy for finally containing the risks of this ominous disease.

While the prospects of "cloning" prion free cattle on the scale of America’s 100 million head cattle herd may seen daunting, Eyestone points out that with the widespread use of artificial insemination in modern agriculture, great strides could be made in as little as six or seven generations.

On a smaller scale, sub-populations of prion-free cattle could be produced for use in other tasks such as the production of pharmaceutical compounds that are eventually used in people, thereby eliminating the risk that a drug produced to promote human health and well-being might accidentally cause the deadly neurological condition.

Jeff Douglas | EurekAlert!
Further information:

More articles from Agricultural and Forestry Science:

nachricht Forest Management Yields Higher Productivity through Biodiversity
14.10.2016 | Technische Universität München

nachricht Farming with forests
23.09.2016 | University of Illinois College of Agricultural, Consumer and Environmental Sciences (ACES)

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>