Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Ecological risks of GMOs come in unexpected ways, model shows

19.06.2002


Introducing genetically modified organisms into wild populations holds a greater theoretical risk of extinction of natural species than previously believed, according to two Purdue University scientists.



William Muir, professor of animal sciences, and Richard Howard, professor of biology, used computer modeling and statistical analyses to examine the hypothetical risks of introducing genetically modified organisms into wild populations.

"We examined these hypothetical situations because the range of new transgenic organisms is almost unlimited," Muir said. "It is constructive for those developing such organisms to be able to anticipate how they could pose a hazard."


The new computer models have shown that the risk of extinction is greater than believed before, identifying three new scenarios in which genetically modified organisms could result in the extinction of a natural population.

"In the broadest sense, this research tells one how to do risk assessment and what GMOs need further containment," Muir said.

In 2000, Muir and Howard found that a release of fish that were larger – and therefore had higher mating success – but also had shorter life expectancy, could drive a wild population extinct in as few as 40 generations. Muir and Howard labeled this the "Trojan gene hypothesis."

But further investigation has found other scenarios that could lead to extinction.

In one scenario, a genetic modification increases the size of the male, which results in the male finding more mates and also living longer. But if the modification also has a third effect of making the male less fertile, the predicted result is that the wild population will be extinct in just 20 generations.

"We consider this an extreme risk," Howard said. "That’s the most severe time frame we’ve encountered so far."

Howard said this risk could arise if fertility was restricted in a genetically modified organism as a way to limit the spread of the gene in the natural population.

"This was the biggest surprise for me, that if you lowered fertility of genetically modified organism the time course to population extinction was faster rather than slower when the genetically modified young have better survival than wild-type individuals," he said. "I still look at the graph of those data and find it amazing."

The researchers also found scenarios in which the introduced gene could spread through the population but not reduce the overall population size. The researchers termed this an invasion risk.

"The invasion risk is an unknown in assessing the overall risk," Howard said. "Given the biology, all we can say is that the gene would increase in the population. We don’t know if that would cause a problem or not. In this case you wouldn’t really know until you actually released the gene into the population."

The results of the research were published in the most recent issue of the scientific journal Transgene Research. The research was funded by the U.S. Department of Agriculture Biotechnology Risk Assessment Program.

The Purdue research is part of an ongoing effort by Purdue and the USDA to determine the risks of biotechnology, particularly transferring genetic material from one species to another, known as transgenic technology.

"Consumer confidence in the use of transgenic technology will only happen if there is a thorough, unbiased examination of the risks," Muir said.

The most recent study found that some of the most significant risks occurred when the introduced gene increased the viability of the adult organism, such as through improved immune response or resistance to a disease or pathogen.

"It’s somewhat counterintuitive that increasing the health of the adult could hurt the overall population, but that is what we found if they had reduced fertility," Howard said.

The scientists say the increased risk from transgenics comes about because such transfers involve one gene from a different species.

"This gene has a mega effect that may confer new functionality on the organism," Howard said.

Traditional breeding, on the other hand, can only affect genes of that species and involves an exchange of many genes, which the scientists call polygenic inheritance.

"Selective breeding is based upon polygenic inheritance where the result is the cumulative effect of many – perhaps hundreds – of genes each with a small effect. In contrast, most genetic modification involves one gene with a major effect," Howard said. "The two methods are not substantially equivalent, although they may be legally regulated as if they are."

Muir and Howard said the genetic background of the modified organism may be a key to potential risk.

A 2001 report by the Royal Canadian Society found that highly domesticated crops, such as corn and soybeans, rarely become weeds in natural settings because "the cultivated species have been genetically crippled through intense artificial selection."

"What this means is that the more wild an animal is, the greater the environmental risk when using that animal to make a transgenic organism," Muir said. "In other words, making a transgenic salmon is going to be more of a risk to the environment than making a transgenic cow."

Muir acknowledges that hypothetical experiments may not reflect what happens in the real world, but he said the experiments err on the side of caution.

"If we show that these plants or animals may be a risk in a laboratory experiment, it could be that they wouldn’t be a risk in nature because nature is less hospitable," he said. "It may be that things we find to be a risk in the lab aren’t a risk at all in nature. We feel that this is a conservative approach to determining the risk."

To get a more accurate assessment of the risk of a genetically modified organism, a facility would need to be constructed that would replicate the natural environment. Muir said some companies are already considering constructing such testing facilities.

"It’s going to cost millions of dollars to build elaborate testing facilities that are as close to a natural setting as possible," he said. "But nobody said this is going to be easy. What’s at stake is important enough to spend that kind of money."

Writer: Steve Tally, (765) 494-9809; tally@purdue.edu

Sources: Richard Howard, (765) 494-8136; rhoward@bilbo.bio.purdue.edu

William Muir, (765) 494-8032; bmuir@purdue.edu

Ag Communications: (765) 494-2722; Beth Forbes, bforbes@aes.purdue.edu;

Steve Tally | EurekAlert!
Further information:
http://www.agriculture.purdue.edu/AgComm/public/agnews/

More articles from Ecology, The Environment and Conservation:

nachricht Upcycling 'fast fashion' to reduce waste and pollution
03.04.2017 | American Chemical Society

nachricht Litter is present throughout the world’s oceans: 1,220 species affected
27.03.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

DGIST develops 20 times faster biosensor

24.04.2017 | Physics and Astronomy

Nanoimprinted hyperlens array: Paving the way for practical super-resolution imaging

24.04.2017 | Materials Sciences

Atomic-level motion may drive bacteria's ability to evade immune system defenses

24.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>