CRISPR Gene Editing: The Future of Invasive Species Control?

HOST INTRO: Invasive species. Destructive plants and animals that hitched rides here on boats, planes and even people. Then multiplied, and in some cases, took over. And like other states, New York has had little success fighting them. But ground-breaking new technology might change that. Wendy Rhodes reports.

RHODES 1:  They’re everywhere. Burrowing beetles that kill trees by the hundreds of millions. Slimy, parasitic fish that suck the life out of their prey. Noxious weeds that cause painful blisters and permanent scarring. And the dreaded . . .

((SOUND – European starlings chirping))

RHODES 2:  Feathery little birds? Well, yeah. European starlings nest together on buildings and can leave droppings over a foot deep. Droppings that makes one million Americans ill each year from E. coli and salmonella.  

The starlings are also responsible for agricultural damage to the tune of almost a billion dollars annually in the U.S. They ravage berry fields and eat grain meant for livestock. They fly in huge flocks, the second largest of all birds, with numbers from the tens of thousands to over a million. And with that many birds, damage can happen quickly.

ZICHELLO 1

They are an invasive species, which is detrimental to crops in certain areas, they can fly into aircraft, which is not good, and they can also carry diseases. (0:11)

RHODES 3:  Dr. Julia Zichello is a scientist at the American Museum of Natural History – she’s studied European starlings for years. We’re walking down Columbus Avenue on a sunny Saturday morning hoping to spot some starlings.

ZICHELLO 2

They’re dark, but they have a lot of purple and green in their feathers. They’re trying to attract mates and look beautiful, which they really do. (0:09)

((SOUND – street noise))

RHODES 4:  We spot some almost instantly, hopping on a grassy patch in the median and poking their beaks into the dirt looking for bugs to eat.

((Sound – Zichello spots some birds. Wendy: Is that one right there? Zichello: Yes.))

RHODES 5:  European starlings were first brought to the U.S. in 1890, when 60 of them were released in Manhattan’s Central Park.  The birds came for the Bard. Birds appear in many of Shakespeare’s plays, like starlings in Henry IV.  A well-meaning Shakespeare lover released the starlings into the park so audiences at outdoor performances could have the complete Shakespeare experience.  Fast-forward 125 years.

ZICHELLO 3

The birds have expanded across the United States extremely rapidly and now we have almost 200 million starlings, just from that one invasion. (0:10)

RHODES 7:  According to the U.S. Department of Agriculture, European starlings are one of the most invasive birds in the United States because of their ability to reproduce quickly and thrive in a variety of environments.

 

Farmers to wildlife managers have attempted to control the starlings by cutting down the trees they nest in and even shooting and poisoning them. But these methods have little impact, so scientists are looking to new technology for answers.

Like Samuel Sternberg. He teaches biochemistry and molecular biophysics at Columbia University Medical Center. He’s at the forefront of a new technology called CRISPR.

(SOUND-Sternberg’s lab)

STERNBERG 1

We just moved in here about a month ago. We can do biochemical experiments here, so we’ll probably have a radioactive bench over here where we’ll do some functional tests of different CRISPR enzymes. (0:10)

RHODES 8:  Sternberg’s new lab is being designed to study CRISPR technology. CRISPR is a new form of gene editing that can change the DNA of plants, animals, even humans. Sternberg explains it as we make our way to his office.

STERNBERG 2

Gene editing sounds very easy when you just say gene editing, but actually what you’re asking is, a protein, this CRISPR machine, to find one stretch of DNA in a side of a human cell that has three billion letters of DNA. (0:15)

RHODES 9:  That precision can make CRISPR more accurate and less expensive than other gene-editing technologies, and as a result, more attractive to scientists looking to use it to control invasive species. Sternberg explains the power of CRISPR in a 2017 book he co-authored – A Crack in Creation: Gene Editing and the Unthinkable Power to Control Evolution. Wait, control evolution?

STERNBERG 3

CRISPR gives you the power to rewrite genetic code and to do so in an inheritable way, and so you really can reshape the genome, which is what makes everything in nature the way that it is. (0:11)

RHODES 10:  So, yes, control evolution. And despite his enthusiasm for CRISPR, Sternberg has some concerns about its readiness as a control method for invasive birds.

 

STERNBERG 4

It might also spread beyond our control, and if it turns out to have unintended consequences that we’re not aware of right now, they’d be very difficult to recall because of this ability to spread without human intervention once they’re released. (0:13)

RHODES 11:  Those unintended consequences, juxtaposed with the excitement about CRISPR’s potential benefits, have prompted flip-flopping within the scientific community. Scientists at Harvard and MIT who published a paper in support of CRISPR, now say we should put on the breaks until further testing is done. While a scientist at Columbia, who published a paper warning of the serious consequences of CRISPR, formally withdrew it and now supports the technology.

But in Western Australia, invasive species are such a big problem, the state government says the potential benefits are worth the risk. And it says Australia may be the perfect location to test this theory out.

MORO 1

Australia is in a fairly good location to consider using gene drives for these forms of wildlife measurement because we are an island nation. (0:07)

RHODES 12:  Dorian Moro is a biodiversity and conservation scientist with the Western Australian state government. He says invasive species are wiping out native plants and animals and throwing off the delicate balance of the environment. So, he’s looking to CRISPR to modify the DNA of invasive species like European starlings.

 

MORO 2

So, the result, is that a selective trait, a genetic trait, for example, sex determination or maleness, can be promoted in a population more rapidly than would normally happen. (0:12)

RHODES 13:  More male starlings would mean fewer female starlings, and as a result, fewer offspring.

MORO 3

And that’s the beauty of population control. Because using CRISPR, if it does work, is that there’s not need then to cull or bait with poisons. (0:13)

RHODES 14:  Poison that every scientist I spoke with for this story says is cruel. It kills indiscriminately – not just its target – the starlings, and doesn’t put much of a dent in the bird’s giant population anyway. Because of all this, Moro says the rewards of CRISPR outweigh the risks.

MORO 4

And I think that that’s the excitement about it. It’s, you know, we don’t want to just stand back and be complacent and do nothing. (0:06)

RHODES 15:  But not everyone agrees that European starlings need to be controlled at all – at least not in New York. Julia Zichello, the scientist with the American Museum of Natural History, says starlings have become an integral part of our ecosystem.

ZICHELLO 4

They’ve been here a long time and since their population is so large, they certainly have a role and a distinct niche, and so removing that would potentially have a dramatic affect. (0:10)

RHODES 16:  Besides, the starlings eat bugs like beetles, flies and snails, which Zichello says is more helpful than what some invasive species do.

ZICHELLO 5

When I think about invasive species and the damage they can do I’ve always thought humans are an invasive species and we do more damage probably than the starlings themselves. (0:10)

RHODES 17:  While the debate over the starlings future continues, there’s another pest that Zichello, Moro and Sternberg all have their eyes on now. The mosquito. They say CRISPR technology could soon transform mosquitos so that they can no longer transmit malaria, one of the world’s deadliest diseases.

For now, European starlings are safe. Scientists say CRISPR will not be ready for widespread use on invasive birds for several years.

 

((Sound – European starlings chirping))

 

Wendy Rhodes, Columbia Radio News.

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