Mosquitoes May Become Our Allies
Posted on: Tuesday, 19 December 2006, 06:00 CST
Without mosquitoes, epidemics of dengue fever and malaria could not plague this planet.
The skin-piercing insects infect one person after another while dining on a favorite meal: human blood.
Eliminating the pests appears impossible. But scientists are attempting to re-engineer them so they cannot carry disease. If they manage that, they must create enough mutants to mate with wild insects and one day to outnumber them.
Researchers chasing this dream, including an N.C. State University entomologist, know they may court controversy. Genetically modified crop plants such as soybeans and corn have become common in the United States, but an altered organism on wings would be a first.
Critics of bio-engineering, especially in Europe, view some genetic alterations as unnatural, even monstrous. People fearful of so-called Frankenfood could sound similar alarms over Frankenbugs.
But with advances in molecular biology and millions of dollars from the Bill & Melinda Gates Foundation, this quest may be within reach. And its promise is huge, the scientists say.
"We're looking at a timeline. But this is coming," said Fred Gould, the NCSU insect expert.
Gould is working on the project with scientists on four continents. They landed $19.7 million under a Grand Challenges in Global Health grant offered by the Gates philanthropy and a National Institutes of Health foundation. The funders selected researchers ready to collaborate rather than compete on risky research aimed at solving massive health threats in poor places.
The genetic tinkering is focused at first on dengue, a tropical virus re-emerging in Asia, Latin America and Africa. While dengue claims a fraction of the million or more victims that malaria kills annually, it strikes 50 to 100 million people each year with severe flu symptoms. Outbreaks disrupt families and communities and overburden health systems.
Dengue is a good starting point because it is transmitted almost exclusively by a single mosquito species (the smallish, striped- legged Aedes aegypti) while the malaria parasite is carried by several. Focusing the effort on just one bug simplifies the science.
To try to build a less dangerous Aedes aegypti, scientists broke a huge job into smaller chunks. First, they needed a means to make female mosquitoes immune to dengue. Only females drink blood (males prefer nectar), and only insects infected with dengue can spread it.
A breakthrough this year at Colorado State University may help. Molecular biologists there stitched laboratory-made DNA into Aedes aegypti that blocks dengue from reproducing in a bug's gut. That stops dengue from getting into mosquito saliva, which deposits the virus into human bloodstreams.
As important, the change sticks. Bugs pass the trait to their offspring.
"Things keep bearing fruit. So far, so good," said Anthony James, a biologist at the University of California Irvine, the lead investigator for the mosquito project.
But inserting strings of DNA into laboratory mosquitoes and spreading them in the wild are two different things.
Scientists must convince the government and people of any country they approach that mutant bugs will fight disease without risk to people or the environment, said Sujatha Byravan, president of the Council for Responsible Genetics.
Scientists are trying to harness exotic genes to help slip dengue- fighting DNA into many offspring quickly. One way: piggyback onto so- called selfish genes -- unusual stretches of DNA that perform no duties other than tending to their own survival.
Whichever strategy gets picked will require a customized release plan. And it will likely carry a cost. Organisms absorbing altered DNA often take a fitness hit, meaning an altered mosquito may fly slower, weigh less or be less successful finding a mate.
Gould and his team aren't engineering insects. They are predicting each strategy's success at passing dengue immunity to future generations. Is it best to release many in a small place or fewer over a neighborhood?
Both jobs require a mix of high-level mathematics and big computing power. But just as important is detailed knowledge of the life cycles and mating habits of Aedes aegypti.
Dengue mosquitoes often are born, live and die in or near a home. They prefer dwellings with no running water, where they can lay eggs in containers people use for cooking, bathing and cleaning. The bugs tend to bite during the day, so mosquito netting over beds offers little protection.
Understanding the life cycles of the insects will give Gould's group clues on how to infiltrate an entire mosquito population quickly and at a reasonable cost.
"We want to determine what's the most efficient way to use the fewest mosquitoes to get this done," Gould said.
Once the scientists select the best strategy, they will test their predictions -- but not in the wild. Plans call for experiments in insect-safe cages surrounding mock homes to be built in sparsely populated land in southern Mexico within two years.
The mock home will copy local dwellings. Inside will be clothing, kitchen implements and furniture. Outside will be potted plants and rain barrels like the ones locals use, all potential breeding grounds.
Mexico was selected because it has experience regulating bio- engineering.
Source: Cincinnati Post/By Catherine Clabby
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User Comments (21)
| 21. |
Posted by Lowell Bethel on 12/19/2006, 17:51 I am a black American guy. I am 42 years old. Are you people insane? Africa cannot feed the people already there. Whay are you trying to accomplish with this? I believe in science, and the American way of invention, ingenuity, and advancement. But we can't feed the people already here. I don't mean to sound heartless. Help the people here already in Africa. Let this theorization take a long needed rest. My God, have you people read the news lately? The trouble in the world at the moment is mind-boggling. Simply staggering. God forgive me, but that's my belief from long hours of thought. Lets work on the people and the problems here........for now. |
| 20. |
Posted by Travis on 12/19/2006, 17:25 I think DDT would be a better solution, but the fight to use DDT is against environmentalist not the governments. DDT was effectively squashed in the courts. As for the entomologist and their genetic work, I am not generally concerned. It sounds as if they are working to make sure this is done in a safe and secure manner. I would like to see proof of oversight though. Some in the post have stated that Killer Bees were a result of genetic engineering gone bad, but that is incorrect. The "Killer Bee" is nothing more than an Africanized Bee. An American scientist living in Brazil was trying to improve honey production by introducing certain traits of the African bee with the European bee. He did not genetically alter the bees that we know as "Killer Bees". In an accident, Africanized bees escaped from the labs and invaded local bee hives. The Africanized bees are very aggressive and quickly took over. The then military government of Brazil coined the phrase "Killer Bee" |
| 19. |
Posted by Mongo Jerry on 12/19/2006, 17:21 Why not just change the human DNA to make us emit a stench so bad that mosquitoes or stingrays won\'t harm us? My vote is to change the mosquito so that they grow as large as chickens, then the Africans will have food to eat. |
| 18. |
Posted by history buff on 12/19/2006, 16:58 With the stroke of a pen which made the use of DDT illegal, Nixon unknowingly caused more deaths than Hitler. Who do we blame for that? The environmentalists? It's so easy to lay blame. Science is producing water filters for 3rd world countries at $40 each. Are they the same one's that did the mongoose thing? Let's ban science! |
| 17. |
Posted by cw on 12/19/2006, 16:57 Anyone remember how we got "killer" bees? The regular honey-bee was genetically engineered to be more resilient, which unfortunately resulted in today's aggressive africanized honey bee. Aren't we all happy now with that science project. |
| 16. |
Posted by Cliff LeVerette on 12/19/2006, 16:47 I say engineer these mosquitoes to carry innoculations to make people immune from disease. Perhaps make it so mosquitoes also carry flouride. Copyright 2006, Sciencephere, Cliff Leverette, President and CEH |
| 15. |
Posted by Human on 12/19/2006, 15:55 Use technology to step forward or sit back in stubbornness and allow people to continue to die. This attitude resulted in millions of Africans starving to death rather than being given GM food grains. No doubt the decision was made by some overweight politician with no sense of reality. |
| 14. |
Posted by Henry on 12/19/2006, 15:55 Why not simply genetically engineer the people so that they cannot contract these diseases? I would point out that no one gives a crap what happens to mosquitoes, but we do care about the animals and insects that ingest the mosquitoes. DDT with discretion has always been shown to be the cheapest and safest method of mosquito control. For all we know birds that eat GM mosquitoes will have soft eggs, too. I hope that adequate scientific study will follow these GM projects indefinitely. I\'m not completely opposed to GM, but the changes that they\'re talking about releasing on the world are probably almost impossible to reverse or undue just as successful natural mutations are. |
| 13. |
Posted by Human on 12/19/2006, 15:53 Use technology to step forward or sit back in stubbornness and allow people to continue to die. This attitude resulted in millions of Africans starving to death rather than being given GM food grains. No doubt the decision was made by some overweight politician with no sense of reality. |
| 12. |
Posted by Human on 12/19/2006, 15:51 Use technology to step forward or sit back in stubbornness and allow people to continue to die. This attitude resulted in millions of Africans starving to death rather than being given GM food grains. No doubt the decision was made by some overweight politician with no sense of reality. |
| 11. |
Posted by James Davis on 12/19/2006, 15:29 Any controversy over this will be short-lived, and laughed at in the future, much the way we\'d now view controversy over heart transplants, polio vaccine, and other commonly accepted medical technologies. The entire history of biology is that of genetic change over time, and because we are part of nature (not outside observers) it is neither inherently good nor bad for us to be involved in such a task. It\'s all a matter of how well we study and manage the process. And the complexity and thoroughness of such study far exceeds what the average armchair critic can imagine. |
| 10. |
Posted by whatever on 12/19/2006, 14:58 A step in the right direction. |
| 9. |
Posted by ZScience on 12/19/2006, 14:47 The lack of humility before nature that's being displa*** here, uh... staggers me. (Dr. Ian Malcolm - Jurassic Park) |
| 8. |
Posted by Kevin Kihn on 12/19/2006, 14:34 I think a better idea would be to alter the females to prefer nectarover blood. |
| 7. |
Posted by Dave Hardesty on 12/19/2006, 14:08 When I hear of things like this coupled with ideas like "Insect-safe" cages in a relatively unpo****ted area of "Southern Mexico" I start to be conserned. Call me a Luddie if you wish but we would do well to remember other entomological experiments gone wrong like Killer Bees and Fire Ants. While I a warm to the idea of using insects to fight insects I am not convinsed there are enough controls implimented in our scientific communities to ensure we don't create a monumental ecological disaster. Especially when conducting experiments in a third world country where there are no real regulations on what they can and cannot do. David mentioned the mongoose experiment on Hawaii to eraticate rats that succeeded in leaving the rat po****tion relatively intact and desimated the local bird po****tions, some to virtual extinction. |
| 6. |
Posted by CLoneZero on 12/19/2006, 13:51 First Frankenbunnies, now spreading gene-enginered bugs. Madness... sweeping changes like this will always go wrong. |
| 5. |
Posted by blamin on 12/19/2006, 13:10 I share David’s concerns. I would like to point out that scientist now admit that DDT, when used properly is not dangerous to humans, or wildlife (except for mosquitoes!). |
| 4. |
Posted by cyrus bear on 12/19/2006, 13:05 Have no fear, the Luddite EUniks will put a stop to this. |
| 3. |
Posted by blamin on 12/19/2006, 13:02 I share David’s concerns. I would like to point out that scientist now admit that DDT, when used properly is not dangerous to humans, or wildlife (except for mosquitoes!). |
| 2. |
Posted by Jon Babbin on 12/19/2006, 12:47 Super-mosquitoes?? |
| 1. |
Posted by David on 12/19/2006, 12:39 Scientists have egos just like the rest of us. They fall in love with their ideas. We MUST spend as much time thinking about what can go wrong IN THE WILD. "Robo-bugs" once deplo*** will be an irreversible decision. For example...Someone thought it would be a fantastic idea to deploy mongoose on the Hawaiian Islands to eradicate rats and mice. Except mongoose feed during the day when the pesty rodents are fast asleep. PURE GENIUS. How this 'minor' detail escaped the minds of the 'scientists' must have every lab rat rolling in their cage in laughter. I think mosquito nets and DEET (however poisonous) seem exponentially benign. Aloha. |
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