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Bioengineering Better Mosquitos
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Here's an interesting piece in Salon on the efforts to produce transgenic mosquitos to help reduce or eliminate malaria.

Due to malaria's 10-day gestation period, scientists can attack the parasite at different places. Jacobs-Lorena blocked the receptor that the parasite binds to inside the insect's mid-gut. James is working on the inverse. Over the past six years, he has figured out ways to block a molecule produced by the parasite that allows it to bind to the insect's salivary glands. In that time, he has reduced malaria levels in the mosquito by 99 percent and feels it likely that he can get the level down to zero within the next year.

A very different approach is being undertaken by Alexander Raikhel at the University of California at Riverside. Raikhel has figured out how to boost a mosquito's immune system. A mosquito's system naturally produces certain proteins in the presence of foreign bacteria. But since malaria is a parasite, not a bacteria, it doesn't normally have to deal with those proteins. Raikhel has figured out a way to trick the mosquito into producing them during the period of time when the malaria sits inside the insect's gut. The result is a mosquito with a turbo-charged immune system that turns on every time there's a chance the mosquito can get malaria -- thus killing the disease before it has the chance to spread.

But the problem with the first line of research is that the mosquitos have to be as fit, or fitter, than their wild counterparts for the genes that block malaria transmission to spread throughout wild populations and do their job.

This may not be a problem for the second line of research, which gives the mosquito "a turbo-charged immune system". These critters may definitely be fitter than their wild counterparts.

But see, this is what worries me about this sort of research. I'm less worried about the unforeseen consequences, and more worried about the foreseen ones. Namely, they're trying to stop malaria by making mosquitos stronger.

Doesn't this seem like an odd way of going about things? During the Black Plague, would it have made sense to make fitter rats and fitter fleas? You may be blocking the worse of two evils, but you're still boosting one of the evils.

The thing is, mosquitos aren't just vectors for malaria.

Mosquito borne diseases are prevalent in more than 100 countries, infecting 300-500 million people and causing about 1 million deaths every year. In India, more than 40 million people suffer from mosquito diseases annually. There are a number of diseases borne by mosquitoes. They are malaria, filaria, dengue, brain fever and yellow fever. Yellow fever is caused by mosquitoes in jungle areas in parts of Africa and South America.

Okay, so you've just made mosquitos who are better at reproducing, surviving, and spreading, but you've blocked their ability to transmit malaria. If there are now more, fitter mosquitos, though, haven't you just increased the transmission of all the other mosquito-based diseases, such as filaria, dengue, brain fever, yellow fever, and our newest friend, West Nile Virus?

Scientists just succeeded in sequencing the entire mosquito genome last year. We've got the keys to the kingdom. And we're going to use that knowledge to make mosquitos fitter?

What, may I ask, in the hell are these researchers thinking?

I don't propose to know all the technical issues involved, but it would seem to me that the focus should be on reducing the numbers of human-feeding mosquitos, wiping them damn near to extinction if possible (don't worry, there are about 2,500 species of mosquito altogether...we can do without the ones that feed on us).

But how would we use genetic information to do this? One possibility might be some sort of Trojan Horse gene that spreads rapidly in a population, is extremely deadly, but only expresses itself after several generations.

Or perhaps we could exploit those microorganisms or other parasites that are harmful to mosquitos but benign to humans. If we're going to try boosting anybody's fitness, it should be those critters that kill mosquitos, not the mosquitos themselves.

Maybe these lines of thinking are not fruitful, and surely they'd carry their own risks and challenges. But the current lines of research, focused on making fitter mosquitos, frankly make me scratch my damned head.

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