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02/01/2012
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Genetically Modified Pests

The Controversial Release of Suicide Mosquitoes

By Rafaela von Bredow
AP

A British biotech lab has released huge numbers of genetically modified mosquitoes in an effort to combat dengue fever. But locals, some say, were not adequately informed of the experiment -- and now a debate has erupted over the potential dangers to humans.

They buzz very, very quietly. That infuriating high-pitched whirring that can rob you of your sleep on summer nights is not part of their repertoire. At this small laboratory near the English university town of Oxford, maintained at a steady 28 degrees Celsius (82 degrees Fahrenheit), the mosquitoes emit no more than a light purr. Their victims can't hear them it until it's almost too late.

Insectophiles might find these animals pretty because of the white markings on their dark bodies. Only the dried drops of blood -- horse blood -- on the gauze lining of their cages reveal how these animals feed.

The insects in question are female yellow-fever mosquitoes, some of the most dangerous animals on the planet. In addition to the illness after which they were named, they also transmit the dengue virus.

Dengue fever is on the rise worldwide and spreading faster than any other insect-borne viral disease. Every year, female mosquitoes infect at least 50 million people in tropical and subtropical regions (the males don't bite). More than 20,000 of their victims -- most of them children -- succumb to their illness.

The mosquitoes at the lab near Oxford serve a rather different purpose: To save human lives. Scientists have implanted a gene they hope will wipe out these mosquitoes' wild cousins. When males from the lab mate with wild females, their larval offspring die within a short space of time. The lab insects have been produced to commit infanticide.

Not Exactly a Villain

Yet something of a scientific thriller has developed around these designer animals. Were anyone to turn it into a horror movie, the story would go something like this: At the heart of the tale there are the managers and scientists at a British biotech firm. These are the bad guys. Their crime: Secretly exposing the unsuspecting inhabitants of a faraway Caribbean island to mutant mosquitoes; a flying army of horrific creatures hungry for people to prey upon. The company -- of course -- is only interested in the huge profits it hopes to make. And then there are the good guys; upstanding researchers and idealistic activists determined to ruin the bad guys' evil plans.

By this interpretation, Luke Alphey would be the head villain of the story, though his boyish looks and lean stature wouldn't exactly typecast him for the role. At the most, his occasional braying laughter would fit the character. Alphey, 48, is the co-founder and chief scientific officer of Oxitec, an Oxford University spin-off. Oxitec headquarters is located in a brick building covered with wild grape in Milton Park, an industrial zone by the road leading to the famous university town.

It was Alphey, a genetic engineer, who dreamed up the idea of the novel insects while he was at Oxford. Today, standing next to the blood-spotted mosquito cages in a disposable lab coat, he defends himself, his company and his mosquitoes. "It was the right time to go out into the field," he insists.

Alphey is referring to the fall of 2009, when he and his colleagues released their designer mosquitoes on Grand Cayman, an island in the Caribbean. The following year they released over three million more of these genetically-modified (GM) mosquitoes.

The experiment will go down in scientific history as the first release of GM insects that could bite humans. What's scandalous about this field trial is that it was largely conducted in secret. Few people on Grand Cayman knew the mosquitoes were genetically modified. The local population was largely kept in the dark.

When the trials were made public a year after the first release of the insects, the locals wondered whether they'd been bitten by these potentially dangerous Frankenstein mosquitoes. Understandably, they felt taken advantage of. "I believe that we are the guinea pigs here," wrote a disgruntled islander on the website of the Cayman News Service. Another asked: "Are we considered so dim-witted and unlearned that we cannot participate in our own environment? Were we considered to be a calculated risk?" Nongovernmental organizations like GeneWatch, a British NGO, have condemned the experiments with GM mosquitoes.

Moths Too

The key question is about what scientists may and may not do. Can they simply release flying, human-biting laboratory-made creatures into the air? And who controls such activity if this is undertaken for a firm that seeks to profit from it?

Companies don't like divulging their plans, preferring to keep their technology under wraps, particularly when it comes to potential dangers. As such, the work of biotech companies must necessarily be the exact opposite of what scientific research ought to be: transparent. That's the crux of the matter.

Despite the Cayman PR debacle, Oxitec is moving forward undeterred. The yellow-fever mosquitoes from Milton Park have since been released in Malaysia. More trials are planned for inhabited areas there, because that's where yellow-fever mosquitoes thrive. They specialize in feeding on humans.

The genetically-modified creatures are also currently buzzing around near the city of Juazeiro in eastern Brazil. Mosquitoes are due to be released in other dengue-plagued countries too, including Panama, India, Singapore, Thailand and Vietnam. They could also soon turn up in Key West, Florida as early as March; preparations there are underway.

And that's just the mosquitoes.

Swarms of genetically modified pink bollworm moths, a plant pest in their natural state, have already been unleashed over the fields of Arizona. Oxitec's latest plan involves another genetically engineered moth, the diamond-back or cabbage moth, which it wants to release in England. In the future, it is hoped, these agricultural pests will likewise mate with naturally-occurring animals to produce dead offspring.

"Oxitec wants to become the next Monsanto," says Gerald Franz, the molecular geneticist at the International Atomic Energy Agency's insect laboratory in the Austrian town of Seibersdorf, referring to the American biotech giant that dominates the business in GM agricultural plants. Indeed, Oxitec already has a monopoly on genetically-modified insects.

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