Genetically modified mosquitoes used to fight dengue, zika in Brazil | Hacker News Reader

Genetically modified mosquitoes used to fight dengue, zika in Brazil

latino.foxnews.com

40 pointsapsec11228 comments

There was a relevant article in 2010 about the concept of eradicating ALL mosquitoes. The author of the study surmised you could do so with minimal ecological impact.

http://www.nature.com/news/2010/100721/full/466432a.html

So how are they breeding these "800,000 genetically modified Aedes aegypti mosquitoes per week" if they by design cannot produce offspring? Through a virus?

The mosquitoes are genetically altered to need a particular chemical in order for their offspring to be non-sterile. (Tetracycline IIRC) Without tetracycline in their food, any offspring the have will be sterile. (I’m afraid I don’t know the details of how this works genetically, but there are probably papers in the literature.)

So the company can happily breed their mosquitoes to keep a stock, feeding them on feedstock that contains tetracycline & then can take a portion of the breeding stock & eliminate tetracycline from their diet - their sterile male offspring can then be released into the wild to mate with fertile wild female mosquitoes.

I’ve heard that one of their client labs had trouble generating sterile males using Oxitec’s protocol: they eventually discovered that the feedstock they were using came from factory farmed chickens which had large amounts of tetracycline in their diet (as an antibiotic it’s used to boost growth rates in factory farmed animals).

(A neighbour works for them, so if anyone has any really pressing questions I can probably ask :) )

Edit: There’s a review paper which looks like it might answer some of your technical questions here: http://longnow.org/revive/wp-content/uploads/2015/02/Alphey-...

"The mosquitoes are genetically altered to need a particular chemical in order for their offspring to be non-sterile."

Life, uh, finds a way.

That's an interesting development. Normally to release a lot of sterile mosquitoes you breed lots of regular ones and then have to sterilize batches. A skeeter with a dietary sterile-offspring switch is really useful.

>Life, uh, finds a way.

But what is the failure scenario? Mosquitos in the wild? There are already mosquitos in the wild, and they are infected with zika and dengue.

Worst case scenario is better than the status quo.

Sorry, that was a popular culture reference.

You were so concerned with with whether or not you could make a pop culture reference, you didn't stop to think if you should.

Wow, I wasn't expecting the Spanish Inquisition!

Fascinating. Thanks for the explanation!

I think it's only a matter of time before someone decides to release a gene-drive mosquito into the wild: https://en.wikipedia.org/wiki/Gene_drive

Apologies if I'm misunderstanding, but isn't this the same thing the article is talking about? In which case, 800,000 have already been released.

NO. The article is talking about releasing sterile mosquitoes. This is a chronic intervention in the sense that you need to continue releasing sterile mosquitoes over time in order to keep populations low. The gene drive technology is a one-shot deal: you release a few mosquitos and a few generations later none of them can be infected with malaria.

It's not the same.

The modified mosquitoes in the article breed sterile offspring. The modification doesn't go beyond that. This has been already done in the wild.

As far as I know, genetic drive have not been used outside the labs. It works by "imposing" the inheritance of a selected gen even if it is bad for the individual.

Theoretically, this could be used for change a full population or even exterminate it. It seems that a first candidate that everybody think about is mosquitoes.

Complete eradication of mosquitoes would be counter productive, especially given that mosquitoes are a major reason some places such as tropical forests have low human activity - http://www.bbc.com/news/magazine-35408835. Selectively countering the harmful traits of mosquitoes appears to be the best way to go about it.

I'd rather people enjoy tropical forests than clear-cut them. I know it's not a binary, but mosquitos don't stop us from destroying rainforests.

Gene drives do not have to be used to eradicate mosquitos (although they can be used that way). They can be used to spread malaria resistance genes to mosquitoes, thereby rendering mosquito populations immune to malaria infection.

http://www.pnas.org/cgi/doi/10.1073/pnas.1521077112

I don't living in an area where mosquitoes spread any diseases, but I would still like to eradicate them just to make it more enjoyable to take a stroll in the forest. I imagine people in the tropics might feel the same.

The only issue I see is that this treatment (by its nature) cannot be self sustaining. Then again, from a business perspective, that's probably a plus.

Yes, as long as even a tiny breeding population survives, this pest will come back. It's probably going to take an annual treatment to keep it under control, at least until such time as we find a permanent solution to rid the world of blood sucking parasites, like blast the surface with a nuclear holocaust, then selectively reseed the planet with only desirable species.

If it lasts for long enough that people stops spreading poisons around to kill the mosquito and let predators grow in number, that'll be already a gain.

It would be nice to have something in our arsenal against dengue fever. I will be interested to see how effective this is.

Dengue vaccines are in last-stage trials and early deployment.

Thanks, I had no idea!

I'm sure there's a movie or two that start with a similar headline...

It seems that Brazil likes a lot to modify insects, they did it too with the Africanized bees: https://en.wikipedia.org/wiki/Africanized_bee

This is how the zombie apocalypse begins...

Powerful new viruses will continue to birth as the Earth warms. A zombie apocalypse might occur regardless of human intervention at this stage.

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