美国国家公共电台 NPR Scientists Release Controversial Genetically Modified Mosquitoes In High-Security Lab（在线收听）

STEVE INSKEEP, HOST:

Scientists have launched a controversial genetic experiment. They started releasing a new kind of genetically modified organism inside a high-security lab. It's a mosquito designed to spread a genetic mutation. This experiment is taking place in Italy, and NPR health correspondent Rob Stein was the only journalist allowed in the lab as the experiment began.

ROB STEIN, BYLINE: To see this new kind of genetically modified creature, I traveled to Terni, a city about an hour north of Rome. Terni's patron saint is Saint Valentine.

UNIDENTIFIED SINGERS: (Singing in Italian).

STEIN: I arrived at a basilica just at the start of this year's Valentine's Day celebrations. Terni is also home to an unusual high-security scientific lab.

RUTH MULLER: Yeah. Hello. I'm Ruth, the chief manager of the facility. Nice to meet you.

STEIN: Nice to meet you, too.

MULLER: OK, go in.

STEIN: Ruth Muller studies insects.

MULLER: We go now into the contained area.

STEIN: Muller punches a security code into a keypad to open a sliding glass door. As the door seals behind us, a powerful blower makes sure none of the genetically modified mosquitoes inside escape. We pass through a second sealed door and blower. Once inside, Muller shows me a small container made out of white mosquito netting.

MULLER: Here we have the gene drive mosquitoes, the genetically modified mosquitoes.

STEIN: They're called gene drive mosquitoes because they were engineered to carry a sequence of DNA called a gene drive.

MULLER: The gene drive is like a selfish gene.

STEIN: A selfish gene because it spreads incredibly fast. It drives through an entire species.

MULLER: All the offspring have done these modifications.

STEIN: Scientists have always tried to prevent engineered organisms from spreading their modified genes. They created this new kind of modified organism using the powerful gene-editing technique called CRISPR.

MULLER: Which is like a molecular scissor which can cut at a specific site in the DNA.

STEIN: And transform the female mosquitoes into mutants - half-female, half-male. Their mouths are male, so they can't bite and spread malaria. Their reproductive organs are deformed, so they can't lay eggs.

MULLER: The females become a bit more male.

STEIN: Like hermaphrodite?

MULLER: Yes, a kind of hermaphrodite.

STEIN: The idea would be to someday release these mosquitoes in Africa to breed with and decimate the mosquitoes that spread malaria.

MULLER: This would really be a breakthrough experiment because we would then understand what we could expect from if they were released in the wild. It's a bit of a historic moment.

STEIN: Malaria sickens more than 200 million people each year and kills more than 400,000. So wiping out the main mosquito that spreads malaria could help finally eradicate the disease.

MULLER: It would be extremely significant because then you would save 450,000 children per year.

STEIN: The project is funded by the Bill & Melinda Gates Foundation, which also supports NPR. And scientists think gene-drive organisms could do all sorts of things - wipe out other diseases - Zika, dengue - save endangered ecosystems. But critics fear gene-drive organisms could run amok and wreak havoc if they were ever released into the wild.

DANA PERLS: This is an experimental technology which could have devastating impacts.

STEIN: Dana Perls is with Friends of the Earth, an environmental group.

PERLS: We can't be taking lightly this extermination technology. We need to slow down. We need to hit the pause button on gene drives.

STEIN: Those fears are a big reason these mosquitoes are being tested here first inside this special lab. It mimics the environment in Africa, but it's in Italy where this species of mosquitoes couldn't survive even if they did escape.

MULLER: We really want to show that we work very, very sound and responsible about this new technologies.

STEIN: Muller leads me to a big, thick, metal door sealing off the most secure part of the lab.

MULLER: We will now enter the experimental chamber.

STEIN: It's hot in here.

MULLER: Yeah, it's hot. It's tropic.

STEIN: Inside, I see a row of six huge cages. The walls are white mosquito netting that stretch from the floor to the ceiling. Each contains hundreds of mosquitoes, the natural kind that spread malaria.

MULLER: So the mosquitoes can fly around like they would do it in the wild.

STEIN: None of these mosquitoes are carrying the malaria parasite. Several of Muller's colleagues suddenly crowd into the chamber. It's time to start the experiment.

MULLER: OK, we can start.

TANIA PERSAMPIERI: Are we ready?

MULLER: Yes, please.

STEIN: As they pull on rubber gloves, Tania Persampieri, the lead technician, carefully picks up a tray holding glass dishes. Each dish contains dozens of immature mosquitoes that have been modified. I can see them squirming around in the water. She walks over to the first cage, squats down and picks up one of the dishes. I'm standing over her shoulder.

She's sliding a glass dish filled with water and the gene-drive mosquitoes through an opening in the netting. So is that it?

PERSAMPIERI: Yes.

STEIN: You just put them in there.

PERSAMPIERI: Yeah.

STEIN: Those are the gene-drive CRISPR mosquitoes.

PERSAMPIERI: Yes.

STEIN: After she's done releasing immature gene-drive mosquitoes, her colleagues slide canisters of warm cow blood into each cage.

MULLER: We heat up the blood because this is attractive for the mosquitoes. They want to have a living (laughter) animal they can bite in.

STEIN: As the researchers are finishing up, the lights in the cage chamber start to dim.

MULLER: It's a slow dimming and also a specific light color, a very orange, very warm color, so that they really feel like having a sunset.

STEIN: That's key because sunset is when male mosquitoes start their mating dance.

MULLER: So the males makes swarms, so it looks a bit like dancing. In these swarms, one female goes in, select a male, flies out and they couple and make babies.

STEIN: Muller and her colleagues hope to know within a year whether their gene-drive CRISPR mosquitoes danced well enough to spread their lethal genetic mutation in the wild.

MULLER: Maybe you can see already if you go a bit nearer, so now they start...

STEIN: Oh, yeah, I see a few mosquitoes starting to do their little dance in there. Oh, OK, it's very romantic that they swarm at sunset.

MULLER: It's very romantic (laughter).

STEIN: Mosquito romance in a high-security lab near a shrine to Saint Valentine to try to prove that a powerful but controversial new kind of genetic engineering can conquer one of humanity's greatest scourges. Rob Stein, NPR News, Terni, Italy.

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