Saturday, March 30, 2024

Science seeks renewed GM debate

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Back in 2000 when the world continued ticking after the Y2K “millennium bug” non-event, New Zealanders were debating an issue that was never going to be resolved as simply as Y2K’s world-ending potential. That issue was genetic engineering, brought starkly into public debate following the publication that year of Nicky Hager’s book on the release of genetically modified corn into New Zealand.
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The book, Seeds of Distrust was a fuse for an issue that quickly exploded into one of NZ’s most bitter election issues, almost inevitably known as “Corngate”.

It culminated in Prime Minister Helen Clark labelling TV3 journalist John Campbell a “sanctimonious little creep” and stalking out of the interview on air about what she did or did not know about the seeds’ release.

Meantime, in the background a Royal Commission was quietly compiling its report on genetic modification (GM).

In 2001 it recommended New Zealanders keep an open mind and “proceed with caution” on the science and what it may deliver a country relying so heavily on crops and protein for its income.

Fast forward 15 years, and the issue of GM appears to have lost little of its fire.

Embattled campaigners like GE Free NZ continue pushing back at researchers’ efforts to study the effects of modified plants and animals.

The GM research sector has since been blighted by quarantine breaches, claims of sloppy field trial containment and some clinical health issues in cloned and modified animals.

And it appears opposition has become more entrenched, with several district councils including Northland and Hastings resolving to become NZ’s first GE Free districts, challenged in court by groups including Federated Farmers.

Massey University molecular genetics Professor Barry Scott said 2000 was a long time ago in terms of scientific advances, but NZ remained the only country to his knowledge to have embarked on the equivalent of a Royal Commission review of GM.

Like many, he believes it may be time to revisit that ground-breaking report.

“It was a big deal, a broad-reaching review that spoke to a lot of different people and one that was headed by some very wise individuals.”

However, Scott was disappointed at the lack of constructive debate that had followed the commission’s report, creating a level of misinformation and misunderstanding about the science and its mechanics.

Far from standing still, the science and techniques of GM have advanced from mainstream methods of 2000.

The early “cut and paste” of gene pieces of the 1970s contrasts with the precise cleaving of specific parts of DNA today, known as gene editing.

“This new technology provides a level of precision for generating mutations in the genome of organisms that hitherto was not possible. Furthermore changes can be made without the use of marker genes, which has been a concern of many opponents to the technology.”

The technology that brought about this dramatic lift in GM’s precision was known as CRISPR – “clustered regularly interspaced short palindromic repeats” (see panel).

CRISPR has been the ground-breaking technology that has taken some obscure work on bacteria’s ability to gain immunity to viral infections, to be at the cutting edge for altering an organism’s DNA.

“You basically design a DNA sequence that will tell an enzyme to go to the exact place on a gene, and make a change to that gene’s sequence.”

Science was full of research and speculation on where CRISPR technology would take researchers.

CRISPR’s key researcher Jennifer Doudna from University of California Berkeley has admitted her own surprise at how quickly her original bacterial research has been adopted, and was now used across biology for modifying plants, insects and last April CRISPR was used to engineer human embryos.

Scott said the technique’s precision made earlier GM efforts seem crude and patched together.

It was also proving extremely cheap, with kit costs down to as low as US$30 for the required RNA, up to 150 times cheaper than some genetic splicing tools.

Like researchers around the world Scott was excited about the potential CRISPR brought, particularly to the human health and agri-sectors.

“Take something like plant breeding. In the past changes were made by chemical or radiation-induced mutagenesis, followed by selection for desirable traits

“But it is very hit and miss. You may get the desired trait, but you also get other less-desirable traits. CRISPR ensures you only get the desired trait, the rest stay the same.”

An applied example was work on the common button mushroom in the United States.

In April, Nature magazine reported how the button mushroom, modified using CRISPR technology to remove its tendency to brown in the refrigerator, could be sold without requiring the US Department of Agriculture’s regulatory approval.

Scott said Chinese research involving gene editing of non-viable human embryos caused an ethical storm.

The science was moving so rapidly regulation was barely keeping up.

“One would hope we see international standards develop, the same way they did over technologies like in-vitro fertilisation in the 1960s and 1970s and recombinant DNA in the 1970s.”

He takes some heart that Chinese and US Academies of Sciences have taken lead roles in urging scientists to refrain from work on human genomes using CRISPR technology until the ethics of use catch up with its possibilities.

 

Is NZ ready for GM revisit?

 

LOGIC: Arguments presented by the anti-GM activists clearly irk Federated Farmers president Dr William Rolleston.

 

After the bitter debates of the early 2000s, Professor Barry Scott believes it is time to review genetic modification (GM) technologies. A review is also something Federated Farmers would welcome.

“Some people will be opposed, as is their right. But I think as a country it behoves us to look seriously at this technology, given our reliance upon biological production, to see what the opportunities are for us,” Scott said

He maintained the rigorous standards of the Hazardous Substances and New Organisms Act (HSNO) meant NZ already had the ability to regulate GM work and another layer of control enabling district councils to ban GM, was simply additional and unnecessary regulation.

His concerns were echoed by Federated Farmers president Dr William Rolleston.

“Farmers I speak to say they would be most concerned if they are prevented by their council from adopting technology, when their neighbour in the next council can pick up on that technology and reap the benefits of it,” Rolleston said.

CRISPR technology may require separation from traditional GM definitions in regulations, and to get better understanding with the public, he said.

With its targeted alteration of a gene or its activity without introducing a new gene, CRISPR differed from transgenics, the GM practice of introducing a gene from another species to deliver a desirable trait.

“If it gets to the point where our customer countries do not consider CRISPR GM, it becomes harder to deny the use of it here.”

The United States was taking a case-by-case approach to genetic editing of produce, resulting in approval of a non-browning button mushroom for example.

The European Union remained stalled with a decision supposed to have been made in March.

In 2015, the Swedish Board of Agriculture ruled some plants developed through CRISPR did not fall within the EU’s definition of a GMO.

A number of arguments presented by the anti-GM activists clearly irk Rolleston.

He questioned the logic of denying such technology when NZ had happily used mutagenesis to improve crops and grasses for almost 80 years. This process blasted the genes of plants with radiation, seeking suitable mutations in a “hit and miss” process.

Rolleston pointed to the ability to compare edited genes to unedited, thanks to low-cost sequencing technology now available

Because it only cost a few thousand dollars to sequence an organism’s DNA, it was possible to compare that base sequence to one altered with gene editing and ensure there had been no peripheral changes to DNA, other than that intended.

He was also frustrated by critics who were happy to accept vaccines and treatments, both human and animal, created through genetically modified processes. This included treatments as basic as insulin, or as complex as the breast cancer drug Keytruda.

“How can a district that declares itself GE free therefore reconcile that with the use of such treatments?”

Given how difficult it was to detect CRISPR changes, there remained the possibility a committed plant breeder could ultimately use the technology undetected and grow it out.

He pointed to trial research done that had the potential to breed crops that reduced nitrogen losses from livestock, drought-tolerant grass and crop species, and even to breed out problem pests like possums as potential applications for CRISPR technology.

What is CRISPR?

CRISPR, or “clustered regularly interspaced short palindromic repeats”, are repeating genetic sequences found in bacteria’s genetic code.

The repeating sequences were interspersed with “spacers”, unique strips of DNA the bacteria have seized from viruses when they have tried to attack the bacteria.

The bacteria effectively hold the spacers as a genetic record of their encounter with the viruses’ DNA. Should the virus return, the bacteria could produce a stretch of genetic material that matched the viruses’ from the “spacer” records.

This “guide RNA” teamed up with DNA-snipping Cas enzymes, programmed by nearby CRISPR genes to hunt down and split or cleave the viruses’ matching genetic sequences, effectively preventing the virus from replicating in the bacteria.

Researchers found by engineering the spacer genetic material the Cas enzymes could be programmed to match the DNA they wished to snip out at specific sites on a cell’s genetic material.

The DNA repair that followed the “snip” resulted in very precise sequence changes in the DNA of the gene of interest.

CRISPR had proven a cheap, effective means of manipulating cell DNA, including mimicking human diseases in kidneys and comparing them to genetically identical control organs.

Agricultural applications had included preventing the browning enzyme effect on button mushrooms, and developing anti-rust strains in laboratory wheat and drought-resistant strains of corn.

Critics reject CRISPR option

Despite a technology claimed to be more precise, cheaper and wide ranging in its application, critics of CRISPR technology maintain it is genetic modification by any definition, and not an option for New Zealand to pursue.

Jon Carapiet, of GE Free NZ and member of the group Physicians and Scientists for Global Responsibility, maintained the principal of genetic manipulation regardless of the method used makes CRISPR simply another approach to an issue consumers rejected.

“We believe organisms manipulated in this or any other GM way should not be released due to the longer-term unknown risks and the lost opportunity to market ourselves as GM free.”

With organics and GE free among the fastest-growing food sectors globally, Carapiet maintained the opportunities to produce sustainable, healthy food for wealthy consumers was there for NZ.

This involved using conventional breeding techniques and greater diversity within farm systems to reduce nutrient losses and improve sustainability rather than genetic manipulation.

“That is an approach supported by work done through the International Assessment of Agricultural Knowledge, Science and Technology for Development, through the United Nations, with a more systems approach to farming.”

Even reducing global food waste would go a long way to addressing food shortages globally, before reaching for GM techniques to produce more.

GM, regardless of technique, was no silver bullet and one that so far had only served to advance corporates involved in broadacre cropping, particularly in the United States, he said.

Perhaps surprisingly Carapiet believed NZ could “have our cake and eat it” with GM techniques like CRISPR.

“We can use GM in lab situations as we do, to identify the traits and genes that deliver them, then use conventional breeding to get there.”

He believed Federated Farmers president Dr William Rolleston would have an uphill battle to try and split CRISPR technology off from GM definitions, but agreed it could be time to revisit the Royal Commission on Genetic Modification’s report from 2001.

“But I don’t know that it will go the way Dr Rolleston thinks it will. Irrespective of the scientific debate, we also need to put consumers and what they want, at the head of it.”

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