Genetic modification offers space-age healthcare, booming agriculture and a new weapon in the war on invasive species – if we choose to use it. Don Rowe reports.
Since the first primordial slime congealed on our infant planet, bacteria and viruses have been locked in a state of total war. Reliant on other living cells to survive, viruses continually devise new ways of attacking potential hosts. Bacteria, with their adaptive immune system, have evolved equally as many ways of detecting and eliminating their foe.
This war, like most, has produced unintended consequences in the realms of medicine and technology, creating new possibilities for science, healthcare and agriculture in New Zealand. But as with nuclear energy following the splitting of the atom, not everyone is keen to get on board. And serious legal hurdles remain for those who do.
Dr Heather Hendrickson, senior lecturer at Massey University’s Institute of Natural and Mathematical Sciences, says a 1987 discovery of a family of DNA sequences was the first step in a scientific story with the potential to rewrite our very genetics.
“Scientists working back then noticed there was this weird little sequence in a bacterial genome that had a repetitive structure to it,” she says. “And in between each of the repeats was a tiny little fragment of DNA that was specific to a virus.”
What they had found was in effect a tiny library cataloguing malevolent viruses. If a virus infected a bacteria and it’s DNA had already been filed away, then a protein within the bacteria could take that sample, check out all the DNA within the cell, and cut away the virus’ alien DNA. Throughout a bacteria’s lifespan they store more and more information in this library, and so learn to defend themselves against different types of viruses. Scientists called this discovery CRISPR – clustered regularly interspaced short palindromic repeats – and the cutting mechanism Cas9.
“Scientists sort of figured out the biology of this thing early on,” says Hendrickson, “but it wasn’t until 2013 that this was turned on its head and used as a gene editing technology.”
It’s an elegant and surprisingly simple process. In theory.
“Basically we’ve got three pieces: the guy that makes the break, the template that we want to be used to repair the break, and the RNA that’s going to help the system to find where to put the break in the first place,” says Hendrickson. “Those are the only parts that you need in order to get this gene editing stuff into a cell.”
Incredibly, the same process works not only in the prokaryotic cells of bacteria, but in animal plant and fungal cells too.
“It works in dogs, it works in yeast, it works in any type of cell that you can just get a piece of DNA into. There doesn’t appear to be a limit. You can make basically any genetic modification to any cell type as far as we can tell.”
The implications are the stuff of science fiction and amphetamine dreams. With a fragment of DNA scientists could change the shape of a woman’s blood cells, reversing severe anemia, or increase the mass of those of a fetus – creating an athletically superior child.
Scientists at AgResearch, a Crown Research Institute with more than 800 staff, have proven that they can use CRISPR technology to remove a major allergen from a cow’s milk. Gene editing also has the potential to enhance endophytes, a pastural fungus that has saved billions in pest control.
In conservation, reducing the fertility of rats, stoats and possums to the point of sterity would rid the country of a dangerous pests without a single pallet of 1080 (a real paradox for the anti-1080/anti-GM crowd).
But, as Hendrickson says, fertile possums are only a problem when they’re in the wrong place. Should a compromised animal somehow make its way to Australia, we would have effectively unleashed a nightmare plague on the native population. And genetic modification in sperm or egg cells create another dilemma too – when you modify germ cells, you’re changing the trajectory of a lineage forever.
“All of their offspring will inherit that same change that you make, and so you get into the issue of consent. Do we have the right to make those kinds of choices?”
Professor Tim Dare, a lecturer in the philosophy of law at the University of Auckland, says technology like CRISPR is forcing us to create ‘a new ethics’.
“There’s no point trying to railroad through something like this. The debate around benefits and risks is both a scientific and an ethical concern – what do we do when we have the capacity to do something, but don’t understand its implications or how it might connect with previous moral history?”
The role of philosophy, Dare says, is to crystallise the issue for debate. In a rising tide of mistrust and skepticism of expertise it’s crucial to set out the arguments as clearly as possible, and to steer clear of ideological hysteria.
“Some debates like those around vaccines and global warming have just been completely hijacked. It’s just a constant battle against misinformation. This is almost bound to be the same. One of the reasons for that which is quite interesting is that the disagreements are often not over detailed matters of fact.”
“When you say to an anti-vaxxer that they are mistaken, what you’re doing is calling into question their entire world view. They’ve got a firm view about the priority of nature and the hubris of Western medicine and so on, and so you can’t attack them on a point of detail because you’re attacking their identity. That’s interesting to me. And it’s bound to be true here too.”
Dr Tony Conner, Science Group Leader at AgResearch, says there is an urgent need for a public discussion about genetic modification. As a food-producing nation, the cost of delay could prove disastrous to New Zealand’s small economy as other nations race ahead.
“The genetic technologies are developing at such a pace internationally that it’s important we don’t get left behind, and as a society that we understand what gene editing is, and what it is not,” he says.
“The difficulty with public perceptions of any genetic technology is that it tends to be skewed in favour of the worst-case scenario, even when there is no real evidence of harm. It puts the onus on us as scientists to communicate what the evidence actually shows.”
Professor Heather Hendrickson and Professor Tim Dare speak at Late at the Museum on Wednesday, October 10. They’ll explore the fast pace of change in our ethical landscape when it comes to genetic science and how its developments influence our society. Read more here, and book now.
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