9 June 2022

Gene-Editing

Tomato vs. hamster.

By Neil Tidmarsh

“My Ministers will encourage agricultural and scientific innovation at home. Legislation will unlock the potential of new technologies to promote sustainable and efficient farming and food production [Genetic Technology (Precision Breeding) Bill].”

This reference in the Queen’s Speech last month was brief but unmistakable – a Bill will soon set genetic engineering free of the laboratory. Is this a cause for celebration (innovations in food production to end hunger around the world, breakthroughs in healthcare to cure deadly ailments and debilitating conditions)? Or is it a source of anxiety (Frankenstein monsters running wild)? Will science fiction’s utopias or dystopias be made real by science fact? Who is the authentic scientist – Dr Jekyl or Mr Hyde?

As it happens, two stories in the news this week neatly illustrated each point of view.

First, the tomato. The tomato plant produces provitamin D3 (a latent Vitamin D) in abundance, but it converts it into a carbohydrate as the fruit ripens. Now biologists at Norwich’s John Innes Centre, using a gene-editing tool called ‘Crispr’, have managed to cut out that part of the plant’s DNA which produces the enzyme that enables the conversion process. So, in the gene-edited tomato, the conversion doesn’t take place and the vitamin builds up and up. The ripe tomatoes are so rich in Vitamin D that eating just two of them would give you all the Vitamin D you needed. Very handy for all of us living in cloudy northern climes where lack of sunlight means that we have to get our supply of this vital bone-teeth-and-muscle builder from our food, which has always been a tricky task, rather than lying on a beach in the Med and letting the sun on our skin do the business for us.

The Genetic Technology (Precision Breeding) Bill mentioned in the Queen’s Speech will probably limit itself to gene-editing and exclude gene-modification. Gene-editing involves cutting out or turning off bits of an organism’s DNA (as with the tomato above). Gene-modification involves mixing DNA from more than one organism (remember Homer Simpson’s ‘ToMacco’, a cross between tomatoes and tobacco, created by mixing tomato seeds and tobacco seeds and planting them alongside plutonium rods ‘borrowed’ from the Springfield Nuclear Power Plant? Highly addictive – and fatally toxic). But even gene-editing has the potential to make neo-Frankenstein mistakes, as this week’s second story suggests.

So, second, the hamster. This innocent creature is not only a common pet, it’s also often used for experiments in biologists’ labs. Scientists at George State University, USA, have used the same gene-editing tool – Crispr – to study the effects of vasopressin, a hormone that regulates aggression and social communication. They’ve managed to deactivate the AVPR1A gene in a group of hamsters; this gene enables the reception of vasopressin in various parts of the brain. So the hamsters, deprived of the hormone, should have become friendlier and less aggressive (though this is hardly a fierce species to start with, surely), if less socially communicative.

In fact, the gene-edited creatures were more aggressive, frequently attacking and picking fights with each other. And more socially communicative (or more socially anxious), scent-marking their cages more often. “We were really surprised at the results” said Professor Elliot Albers. “We anticipated that if we eliminated vasopressin activity, we would reduce both aggression and social communication – but the opposite happened… This suggests a startling conclusion. We don’t understand this system as well as we thought we did.”

So there we have it. A benign future where clever scientists and enriched tomatoes and other miraculous foods will eliminate ailments such as rickets (and the boredom of lying on a beach) once and for all? Or a malign future where reckless scientists, poking about in mysteries eternally unfathomable to man, unwittingly create ferocious Frankenstein monsters which will escape from the lab, attack us in our own homes, pee in every corner and all over our furniture to mark out its territory and breed with our pets to produce a super-aggressive species which will take over the whole world? (And who wouldn’t say that it serves us humans right?)

But Shaw Sheet is a rational, optimistic and enlightened organ, so we’ll let Professor Albers have the last word on the ‘gene-editing – good or bad?’ question. He recognises that “the counterintuitive findings” of his experiment have opened up the need for more investigation (“we need to start thinking about the actions of these receptors across entire circuits of the brain, not just in specific brain regions”) which may well lead to invaluable discoveries (“the neurocircuitry involved in social behaviour, and our model, has relevance for human health; understanding the role of vasopressin in behaviour is necessary to help identify potential new and more effective treatment strategies for a diverse group of neuro-psychiatric disorders from autism to depression”).

And that sounds like good news for human beings. If bad news for hamsters.