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These mosquito larvae in a lab at Imperial College in London have been genetically engineered

to glow red under a laser.

But that red fluorescence is just a marker -- Its there to tell the researchers that

something profound has happened.

I ran out and I grabbed my supervisor ... I was like Tony but you know you've got

to look at this.

So we started going through and I read them off one by one and I was like red, red, red,

red and we just...

It was a very crazy time.

We just started screaming and getting super excited.

Since only one of their parents had a copy of the red gene, youd expect around 50%

of the larvae to be red.

But nearly 100% of them were glowing.

The researchers had hacked the rules of inheritance with whats called a gene drive.

But the red gene isnt the point - its been linked to a genetic tool that renders

female mosquitoes infertile.

And thats a huge deal because this isnt just any old mosquito species.

This is anopheles gambiae, one of the mosquitos that carries the parasite

that causes malaria.

So malaria is mostly a sub-saharan African disease.

It affects people in the Indian subcontinent, Southeast Asia, but its primarily a disease

of Sub-Saharan Africa.

And the majority of malaria deaths in any given year in the world, hundreds of thousands

of deaths, are kids under 5 in Africa.

Over the past 15 years, theres been a big investment in bed nets, insecticides, and

better treatment.

And I think the result has been a lot of steady progress on malaria.

That being said, its progress against a really, really high death rate.

Most African countries really want to try to eliminate it and WHO is really in support

of this, theyve set some targets to achieve in 2030.

And where we stand now, we dont seem to be on course for achieving those.

While researchers continue to work on a vaccine, genetic approaches to malaria look increasingly


Genetically modified mosquitoes arent new - a company called Oxitec has released mosquitoes

in Brazil that are designed to have nonviable offspring.

But those dont contain a gene drive, which biases inheritance so that the modification

continues to be passed through a population, though they can also be designed to have a

more local reach.

The idea of driving desirable genes into insect populations dates back decades,

but progress toward that goal jumped ahead after the invention of the CRISPR gene editing

tool in 2012.

CRISPR allows scientists make precise changes to DNA in the lab.

A CRISPR gene drive could let them push those changes through a wild population of insects.

It works by inserting the gene editing tool itself into a chosen segment of the mosquitos


From there, CRISPR induces the cell to copy the package onto the matching chromosome.

Like us, mosquitoes have 2 copies of each gene, one from each parent.

And now that the gene drive is on both chromosomes, it will get passed on to all the offspring,

where it will copy onto their other chromosome, and so on.

So depending on what biologists attach to that package, like the red fluorescent gene,

they can make some drastic changes to wild populations.

There are two broad approaches to malaria mosquitoes.

The team at Imperial College is part of an international group called Target Malaria,

funded mostly by the Bill & Melinda Gates foundation.

And theyre aiming to use gene drives to suppress mosquito populations.

Their drives are designed to spread female infertility or to prevent females from being

born, with the effect of shrinking a population of mosquitoes.

Then theres a team of researchers at the University of California institutions

who have been developing a gene drive that alters, rather than shrinks, the mosquito population.

It spreads genes that make mosquitoes resistant to the malaria parasite, so they dont transmit

it between humans.

The World Health Organization has outlined the steps that G.M. mosquitoes should go through

before being deployed. Gene drive research is in phase 1 now,

but to find out if it could really work, they need to test it outside of a lab.

And the researchers say their mosquitoes should be ready for phase 2 soon.

I'm hoping the science is well within five years.

Maybe even half that.

Maybe in one or two years.

A couple of years.

But then that's in the lab in London.

After somethings ready in the lab in London you'd really want to go through very rigorous


So with every health intervention or technology theres kind of a spectrum of how much testing

and how much certainty people require before they just try it.

This is always a trade-off in any medical trial, if you develop a drug and its a

miracle and it helps everyone, when do you stop the trial and just start giving that to everyone?

Once we have a gene drive that we can release in the wild that could wipe out malaria, every

year we dont do that is 500,000 to 700,000, mostly kids, dying.

Kevin Esvelt the MIT scientist whos working on gene drives,

was talking to me and he said Malaria is a case where there are really strong

ethical argument of doing something now today because so many children have died just in

the time that we've been speaking.

I would say at least 20.

And his takeaway from that wasnt lets do this as fast as possible.

Its lets do this right, because if we dont do this right, then theres going

to be a massive backlash and were never going to be able to do anything like this

ever again.

Yeah if you move forwards with a unilateralwe are going to save the kids whether you

like it or not,” really does imperil the broader malaria eradication effort.

Target Malaria has begun a lengthy process of building facilities and staff in 4 African

countries, where theyll be working with non-gene-drive mosquitoes before importing the

gene drive mosquitoes.

And even then, theres more lab work to do before an actual release.

So the modified one is modified using a laboratory strain.

So you have to do experiments to make sure you incorporate the natural genetic background

of the mosquitoes in the area where you want to work.

At each stage, theyre consulting with local communities and with governments about this

genetic technology thats designed to spread across borders.

There are no regulators that have handled this before.

Not only just in Africa, but anywhere.

I think im curious about you know this notion that we have a public conversation,

we need to get people on board, this notion that that would somehow lead to some clear

consensus or some clear green light.

At some point someone has to decide.

And Im curious if you have a sense of who that is.

Yeah, thats the million dollar question and no one I talked to even pretended to have

the answer.

The end game that got alluded to by a lot of people was some kind of agreement by the

African Union about releasing a self-propagating drive.

One tricky thing is malaria does not solely

infect people in democratic countries like Ghana or Senegal.

It also affects people in the Democratic Republic of the Congo,

which despite the name is a dictatorship. Countries with

really unstable and in many cases really awful governance.

So one tricky question is, if the African Union comes together and says yeah were ok with

this, is that legitimate?

Are they speaking for people in Africa?

And I think a lot the work that scientists are doing is trying to reach out before that

and trying to start a conversation before that to make sure its legitimate.

As the public debate begins, theres a risk that the politics of genetically modified

crops could spill over to the mosquito issue.

Anti-GMO groups like Friends of the Earth have already called for a moratorium on gene

drive research. They fear it will be misused by agribusiness and militaries and cause unintended

damage to ecosystems.

No one in this is as big of a son of a bitch as nature.

Like, nature is so awful in every conceivable way.

It is completely indifferent to suffering.

But I think many of the things we look back on as humans as our greatest achievements:

getting rid of small pox, penicillin, insulin for diabetics, mass vaccinations.

Those are all things that involved messing with nature and either repurposing or tweaking

things that nature created, for our own uses.

Some of the worst things weve made have also done that.

But I look at the earth as something we've got to keep going for us and other

animals but I dont look at it as this morally benevolent place.

Its a horror show that were trying to manage as best we can and this is an ambitious

but really interesting way to manage it.

For a bunch more information about this fascinating topic,

go read Dylan's feature article on

I'll put a link in

the comments. And if you're interested in genetic engineering more broadly,

we have an episode on our Netflix show

called "Designer DNA," and it's about genetic engineering in human beings.

That's on Netflix, go check it out. Check out all the other episodes too,

we're publishing them weekly on Wednesdays.

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