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Tasty transgenics

AquaBounty Technologies made big news when they announced they were getting close to approval for their fast-growing transgenic salmon, but this isn't the only transgenic project with its eyes on our food supply.

By | July 28, 2010

AquaBounty Technologies made big news when they announced they were getting close to approval for their fast-growing transgenic salmon, but this isn't the only transgenic project with its eyes on our food supply. Several other projects are underway to develop transgenic animals that may eventually make their way into agriculture's mainstream and end up in your grocery aisle. And scientists aren't just interested in bigger animals -- they're also looking at making meat that's more environmentally friendly, and healthier.

A cleaner pig

Enviropigs
Image: University of Guelph

The stereotype of pigs as dirty animals is being challenged by the University of Guelph's "Enviropig," which, while growing at a normal rate, produces less waste and needs less food. The pig was specifically created to solve the environmental run-off problems of pig farming. Normal pigs can't digest phytate, which makes up around 50-75 percent of phosphorus present in cereal grains, corn and soybeans -- the pig's main food. This excess phytate comes out in their waste, and they need to be fed additional phosphorus in a digestible form. The Enviropig contains a gene from E. coli called phytase, which encodes an enzyme which metabolizes phytate molecules into readily absorbed phosphate. As a result, it eats less feed and produces less waste, including 30-65 percent less phytate waste, which in turn decreases the chemical contamination of agriculture drainage areas. "We originally set out to help farmers around the world reduce the environmental impact of raising pigs," said Richard Moccia. The University owns the rights to the pig, and has been in the process of getting approval from both the U.S. Food and Drug Administration and Health Canada since 2007. Health Canada is satisfied that the Enviropig does what it says it does, and will not harm the environment, but the university is still in the process of assembling documentation of the safety of Enviropigs for human consumption. Approval, if it happens, is at least a few years off, said Moccia.

Fat-friendly meats

Omega-3 piglets
Image: Jing Kang,
Harvard Medical School

Omega-3 fatty acids are trendy, and for good reason -- their consumption is linked to better cardiovascular health and lower risks of diabetes and cancer. But they can be hard to come by in a land-locked diet, since they are only produced by plants and lower life forms, such as algae in the ocean. Farm animals fed a diet consisting mainly of grain, soybeans and corn don't consume much omega-3, and naturally contain only omega-6 fatty acids, which don't have the same health benefits. "We realize the huge imbalance in omega-6 to omega-3 in the human diet," said Jing Kang at Harvard Medical School. "We want to decrease the omega-6 and increase the omega-3." Kang has inserted the fat-1 gene from C. elegans into pigs, which allows them to convert the omega-6 fats found in their normal feed into omega-3s. Kang is currently working on other animals, such as chicken and fish, and also vegetables which don't usually contain omega-3, like tomatoes. Kang is looking for a company to commercialize the technology, and to help with the time and expense of dealing with regulatory issues, and couldn't offer a projection of when the food could hit the market.

A fatter salmon

An AquaAdvantage Salmon and
its non-transgenic sibling

AquaBounty Technologies

The AquaAdvantage salmon grows twice as fast as regular salmon, reaching full growth in captivity by 200 days, instead of 400. The salmon grows faster because researchers inserted the gene for a growth hormone from the Chinook salmon (which grows much faster) into Atlantic salmon eggs. In theory, the AquaAdvantage salmon could provide relief to the ongoing pressure on natural fisheries, and, because it is grown in pens built on land, cut down on the environmental impact of shipping fish from the coasts. The AquaAdvantage salmon is the transgenic animal closest to getting FDA approval for human consumption, having passed five sections of the FDA's seven-part application. The company has submitted all the remaining required information, and is expecting a decision soon. AquaBounty is also working on implementing the same growth-hormone technology in tilapia, shrimp and other important aquacultures, said Val Giddings, a consultant who worked for the food and agriculture division of the Biotechnology Industry Organization for a decade and has worked with AquaBounty.

Big fish, mutant cows, flu-resistant birds

Terry Bradley, an aquaculture researcher at the University of Rhode Island, has produced rainbow trout with six-pack "abs" and hulk-like shoulders by blocking the fish's myostatin gene, which inhibits muscle differentiation and growth. BioDak, LLC is producing cows that are resistant to bovine spongiform encephalopathy (the prion-based "mad cow disease"), as well as cows that don't produce antibodies, for research purposes. Laurence Tiley from Cambridge Veterinary School is working with Helen Sang of the Roslin Institute to produce chickens that are immune to the flu virus, hopefully decreasing the impact of avian flu on chicken stocks. Their technique includes introducing the antiviral protein Mx into the chickens and inserting small RNAs to disrupt the flu virus.
 

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Comments

Avatar of: Elisa Glover

Elisa Glover

Posts: 1

July 28, 2010

Sorry, had to put my 2 cents in.\n-A vegetarian scientist
Avatar of: anonymous poster

anonymous poster

Posts: 20

July 28, 2010

I can hardly believe such a wonderful thing is possible.
Avatar of: anonymous poster

anonymous poster

Posts: 1

July 28, 2010

If farm animals were fed their natural diet, such as grasses, instead of soy and corn, their meat would be higher in omega-3 instead of omega-6. Why not feed animals their natural diet instead of developing mutant meat?
Avatar of: anonymous poster

anonymous poster

Posts: 107

July 28, 2010

Ironic that Jennifer Welsh should have chosen the title "Tasty Transgenics" for an article on food that manages to totally ignore the question of how it tastes. \n\nOf course, the fault lies not in herself, but in her subject. The agriculture industry in general and agricultural geneticists in particular have almost entirely forgotten that humans have taste buds. The revolution in agricultural genetics has given us abundant inexpensive food that, for the most part, tastes like crap. The reason is simple. The customer of the agricultural geneticist is the farmer, who is far more interested in the cost, yield and mechanical harvestability of his crop than in how it tastes. Genetic engineers certainly didn't start this trend, but they have become a lightning rod for criticism of it. \n\nA tip of the toque to Jing Kang, who at least has her eye on the consumer, and is trying to make food healthier if not tastier.
Avatar of: Tarakad Raman

Tarakad Raman

Posts: 1

July 31, 2010

Proponents of Bt-gene technology in India, especially those who are very keen to get approval for commercial cultivation of Bt-aubergine, wrongly perceive or project opponents of the technology as anti-Genetic Engineering. Those opposing Bt-aubergine are not against GE, but are mainly or exclusively concerned about the possible or proved deleterious effects of Bt-gene, and, in actuality, most of them are strong advocates of the use of Genetic Engineering for increasing crop productivity and crop quality. They do believe judicious application of GE promises to bring about a second "green revolution", but one cannot afford to be reckless, especially where there is scientific basis for apprehensions. \nIn the light of the above, information contained in Jennifer Welsh's post "Tasty transgenics" is valuable and encouraging, although it does not contain any news about GE-plant foods. On the face of it, transgenics described in the article appear to be quite safe as far as human health is concerned. The article should be read by all interested people.
Avatar of: anonymous poster

anonymous poster

Posts: 35

August 5, 2010

There are many potentially good and bad things about transgenics, and there's reason for hope and worry about them. Enviropigs may relieve the burden of phosphorus on waterways... but what happens when pigs with lower nutritional needs go feral? Increasing omega-3 fatty acid is a good thing in general... but fatty acids are an intricate code, that influences a vast array of signalling molecules. Will introducing one gene out of the biosynthesis pathway make all these compounds more healthy, or will some become more unhealthy?
Avatar of: Nicoles Williams

Nicoles Williams

Posts: 1

August 26, 2010

The applications for this are trendmendous! You can cross-breed and enhance native species in a variety of ways.
Avatar of: Jennifer Welsh

Jennifer Welsh

Posts: 1

August 27, 2010

The FDA recently announced that it will begin the process of considering the AquaBounty fish for the commercial market during two public meetings, on September 19-21 -- I'm eagerly awaiting the results. \n\nThanks for reading!\n\nJennifer Welsh

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Mettler Toledo
BD Biosciences
BD Biosciences