Spicy Tomatoes, Hangover-proof Wine: Is There Anything CRISPR Can't Do?

Lately, there's been a lot of buzz about mosquitoes; specifically, the genetically engineered variety. This summer, a team of scientists from the University of California, Santa Barbara and the University of Washington pioneered a method for messing with mosquito vision, making it very difficult for them to find human targets.

How did they accomplish such a feat? Using a genetic engineering tool known as CRISPR.

"CRISPR was originally a way that bacteria developed to fight viruses," says Raphael Ferreira, a genomics engineer at Harvard Medical School. Often compared to a pair of "molecular scissors," CRISPR uses specialized proteins called Cas — short for CRISPR-associated enzymes to cut strands of DNA or RNA at a precise, preprogrammed location. Then, the system can insert or remove the desired gene at that site, and viola: gene-edited organism.

CRISPR opens up a world of possibilities, including many — such as blinding mosquitoes — in the realm of human health. But that's not all it's being used for. "We have so many variants of that technology, it has allowed us to do any type of genetic engineering possible," says Ferreira.

Here are some of the wildest ways scientists are applying CRISPR inside (and potentially outside) the lab.

1. Growing Spicy Tomatoes and Decaf Coffee Beans
Imagine biting into a vine-ripened tomato. What flavors come to mind? Sweet? Acidic, maybe a little savory? How about spicy?

Thanks to an international team of geneticists, that might be the future flavor profile of the humble tomato. Researchers in Brazil and Ireland have proposed CRISPR a means of activating dormant capsaicinoid genes in tomato plants, the same genetic sequence that gives chilis their kick. In addition to creating the perfect bloody Mary, the plants promise an economical alternative to traditional peppers, which are notoriously tricky to grow.


CRISPR can also offer a boost to your daily breakfast routine — or take the boost away. U.K. company Tropic Biosciences is currently developing a coffee bean engineered to grow caffeine-free. That's a big deal, because today's coffee beans have to be chemically decaffeinated, usually by soaking them in ethyl acetate or methylene chloride (also an ingredient in paint remover). This harsh chemical bath strips out both the beans' caffeine and much of their flavor. CRISPR coffee promises a jitter-free cup of Joe, with all the roasty goodness of full-caf.

2. Making No-Hangover Wine
If you've ever wished you could have a night out on the town without suffering a head-splitting hangover the next morning, you might be in luck. A team of scientists at the University of Illinois have used their genetic scissors to boost the health benefits of a strain of yeast used to ferment wine — and they've snipped out the genes responsible for next-day headaches.

Saccharomyces cerevisiae, the yeast in question, is a polyploid organism, meaning that it has many copies of each gene (as opposed to the usual two). This feature makes the yeast both highly adaptable and extremely difficult to genetically engineer using older methods, which could only target one copy of a gene at a time.

But CRISPR allows genetic engineers to cut across every single version of a gene in one go. Compared to older technologies, "the complexity of what you can do with CRISPR is way beyond," says Ferreira, "It's all about efficiency."

Using it, the Illinois team was able to boost the amount of heart-healthy resveratrol in their wine, while leaving the hangover on the cutting room floor.
3. All Bull, No Fight
When it comes to cattle farming, horns are usually a no-go. On a fully-grown bull, they pose danger to the farmer, the other cattle, and occasionally to the animal itself.

Traditionally, farm-raised cattle are dehorned by annihilating the horn-producing cells on the animal's forehead, located on two bony protuberances called horn buds. The buds are destroyed by one of several different painful means: with good old-fashioned knives, or by applying hot irons, electricity, or caustic substances like sodium hydroxide. These practices can sometimes lead to facial disfigurement or eye damage. But CRISPR might just offer a more ethical alternative.
4. Resurrecting Lost Species
Perhaps the most far-out use for CRISPR at the moment is its potential to bring entire species back from the dead. And right now, there's serious talk about resurrecting one particular species: the passenger pigeon.
Now, scientists are looking to CRISPR as a way to bring these iconic birds back. California-based biotech organization Revive & Restore has a dedicated Passenger Pigeon Project, which aims to reestablish the species by modifying the genome of the closely related band-tailed pigeon. If successful, the group says, they could use this approach to resurrect all kinds of extinct or critically endangered creatures, from the black-footed ferret to the woolly mammoth. Whether or not they should is, of course, still a matter of some debate, but there's no denying that CRISPR has made the stuff of science fiction possible.