Mammalian Gene Drives Set To Overhaul Evolution - If We Let Them

 Source: Science News

Source: Science News

I'm a brain person. For the most part, I'm content with just writing about the brain.

But a conservation story caught my eye a few weeks ago and I haven't been able to let go.

Here it goes: by 2050, New Zealand wants to rid itself of all vertebrate invasive species. We're talking all the mice, possums, rats, weasels and other rodents. The reason is that they've been wrecking havoc on New Zealand's delicate ecology, fighting for resources with other native species such as the kiwi and tearing into the island's agricultural profits. 

It's a hefty (and somewhat insane) goal, and to get there scientists are starting to develop a "nuclear option", so to speak: a mammalian gene drive, which has the potential to wipe out entire species.

Previously gene drives have only been tested in yeast and insects. A huge effort, funded by the Gates Foundation, is now trying to use it to make malaria-resistant mosquitos in an attempt to thwart the disease.

In a nutshell, gene drives are snippets of artificial DNA that screw with inheritance.

Lets say scientists added a gene to a mouse that makes it more sensitive to poison or unable to reproduce. Say they used the gene editing tool CRISPR. When this animal breeds with a mate in the wild, the engineered gene gets passed down to only some of the rodent babies. Repeat a few more generations, and it basically gets diluted out of the population. 

Gene drives are brilliant in that they add the tool CRISPR along with the poison gene. Basically, gene drives give a mouse the ability to edits its own DNA. Now when the engineered mouse breeds, its babies get a copy of the CRISPR tool, which snips their DNA to introduce the poison gene. When they grow up and eventually have babies of their own, the same process repeats, until most of the population has the poison gene. Gene drives are basically a perpetual motion machine for gene editing.

According to one estimate, a gene can go from 1% to 100% in 10 generations. That's crazy fast. 

And obviously crazy dangerous. It doesn't take much for such a mutant to radically transform an entire species. New Zealand, being an island, may be a good place to test out the tech on animals that can't escape (eg, those that can't fly). But even then, the consequences of tampering with nature is unclear.

That's not to say we shouldn't proceed. And given the global nature of the technique, the scientists involved stress that the work needs to be developed in the public eye. 

Read more about the story at Singularity Hub, and let me know: is the risk worth the promise?