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MIT researchers propose release of genetically engineered mice on Nantucket

NANTUCKET, Mass. -- On the picturesque island of Nantucket, residents are considering a radical approach to fight a disease that's haunted the island for decades.

Dr. Timothy Lepore says he sees upwards of 100 cases of Lyme disease each year, an especially high number for an island with a population of 10,000 residents.

One of those patients is Illya Kagan, a painter who was first diagnosed with the tick-borne illness when he was a teen.

"I was suddenly fatigued and then had a bullseye rash," said Kagan.

It was a few years later when it came back that scared him. "I woke up one morning and half of my face wasn't working" said Kagan. 

The temporary paralysis is called Bell’s Palsy and is a potential side effect of Lyme disease.

Kagan says he’s been infected five times, something Dr. Lepore said isn't uncommon on the island where as many as 30 percent of households deal with Lyme disease.

Finding the source of the problem

Ticks live in shrubs and underbrush, waiting for an unsuspecting animal to come by that they can latch on to.

Deer and mice are some of the most common targets, but people are also unsuspecting victims.

On Nantucket, the high deer population is directly correlated to the amount of ticks. One possible solution was to reduce their numbers, but that was unpopular with residents, Lepore said.

The white footed mouse is another common tick target. According to researchers, it’s the biggest carrier of Lyme disease on the island making it a prime opportunity for experimenting with new techniques to reduce transmission to humans.

Experimenting with genetically modified rodents.

MIT evolutionary biologist Dr. Kevin Esvelt has developed an idea to modify the mice native to the island and release hundreds of thousands into the environment.

"Ticks aren't born infected, they usually get infected when they bite an infected mouse," Esvelt told Boston 25 News.

Esvelt is director of the Sculpting Evolution Group and had the idea to engineer mice that are immune to tick-borne diseases. They call it “Mice against Ticks” and the hope is to flood Nantucket with enough of these genetically engineered mice, that they would pass the immunity gene down to their offspring for multiple generations. 

"We'll disrupt the cycle of transmission and there will be many fewer infected ticks in the environment and there for many fewer human infections,” Esvelt said.

Esvelt says they’ve already identified the genes necessary to engineer the immune mice and it's now time to put the theory to the test. He says they’re also offering the option of altering the mice’s genes so the ticks won't feed on them.

"Ticks that bite the mice, well the mice will taste bad, sort of like mouse blood becomes hot sauce and so the ticks will fall off and most won't find another host and so they'll die," he said.

Planning and testing before going full-scale

The plan is to first test the mice on an uninhabited island before releasing them on Nantucket, which Esvelt estimates is at least seven years away if everything goes perfectly.  If the experiment drastically reduces the amount of tick borne disease on the island, Esvelt said he believes the genetically engineered mice could eventually be used on the mainland. 

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