Gene-editing technologies could be deployed against pests like rats - but their use throws up a raft of prickly issues. Photo / File
Gene-editing technologies could be deployed against pests like rats - but their use throws up a raft of prickly issues. Photo / File
Kiwis are being urged to have their say on gene-editing technologies, as our leading body for science today sets out how they could be used to combat pests or replace faulty genes.
Gene editing has been at the centre of a fast-moving global revolution, fuelled by advances such as the CRISPR-Cas system that's effectively given scientists "molecular scissors" to snip and splice DNA.
But the technology, which remains strictly regulated in New Zealand, has also thrown up a raft of prickly ethical, legal, environmental and social quandaries, and Royal Society Te Aparangi has convened a panel of experts to tackle them.
In two discussion papers released this morning, the panel looked at how gene-editing could stop the spread of pests and treat diseases.
"One scenario we explore in the pest control paper is using gene editing to stop possums from reproducing in New Zealand, to reduce the burden on our native plants and animals," said panel co-chair and Massey University molecular geneticist Professor Barry Scott.
"Practically there would be some challenges as no one has gene edited marsupials yet and there is uncertainty around how to build a suitable 'gene drive' to reduce fertility in the possum population."
From an ethical standpoint, he said, some may prefer this approach to pest control as it removed the need to use poison or traps.
"But then there is the risk of what happens if gene-edited possums get to Australia, where they are a protected species and an important part of the ecosystem.
"Regardless, there is still much research required and it is likely to be many years before such techniques are sufficiently refined to use them."
Another scenario investigated gene editing invasive wasps - something that also hadn't been carried out before, but had been with honeybees.
Wasps had a division of labour dependent upon whether they were reproductive or not, which could mean significant and unknown consequences of a gene drive system.
Like possums, pest Vespula wasps were also valued and important in their native home areas, in Europe.
But a genetic solution could combat a scourge held responsible for around 20 per cent of North Island beehive losses in 2015, and now found in New Zealand in their highest density.
In stoats and rats, the use of gene drives to control wild populations of rodents and stoats would likely require the breeding and repeated release of very large numbers of altered animals over large areas.
Possums are New Zealand's most significant mammalian pest. Photo / File
The panel reported that eradicating rats in New Zealand, where our ecosystems were free of rodents up until human arrival around 800 years ago, may have few knock-on effects.
However, in other parts of the globe the effects on natural systems might be very different.
Rats were excellent invaders, dispersed well, and hybridised with closely related species, making accidental release and spread of gene drive modified rats a serious consideration.
Similarly, stoats are an important animal in northern European ecosystems, so even the prospect of such an incident could mean the need for a means to turn off any gene drive.
Scenarios in the panel's healthcare paper, meanwhile, explored potential ways to cure or prevent disease in a person, or reduce disease risk or enhance biological function in offspring.
"Perhaps New Zealanders might feel comfortable using gene editing to cure a disease in an individual, especially for one of the 3000 disorders linked with a known gene mutation," Scott said.
"But they may be opposed to germline therapy, which can pass changes on to future generations."
There were methods available to avoid the transmission of disease controlled by a single gene, notably the BRCA1 gene that's known to raise the risk of cancer.
A patient might employ in vitro fertilisation and to use CRISPR to revert any mutation-bearing embryos back to a version of the gene not associated with the disease - something banned under current law.
Another patient, with a family history of early deaths through coronary artery disease, linked to high blood cholesterol, might request gene editing their liver to influence a cholesterol-lowering effect.
But while that proposed modification occurred naturally, introducing it through gene editing might lead to it interacting with other genes to produce adverse effects.
"In producing these resources we sought to set out relevant considerations on how, practically, gene-editing techniques could be applied in these areas, as well as highlight important legal and ethical considerations to help people engage with the topic," Scott said.
"The technology of gene editing offers society a wide range of opportunities such as curing diseases and eradicating pests but, like all new technologies, there are uncertainties and there may be areas where collectively we are comfortable to use the technology and areas where we are not."
'No plans' to change laws - minister
In New Zealand, no one was currently advocating for the use of the experimental and untested technology of gene drives as conceived in their most basic way.
Our approach-with-caution approach to genetics has remained the status quo since being recommended by the Royal Commission on Genetic Modification nearly two decades ago, and remains subject to laws like the Hazardous Substances and New Organisms (HSNO) Act and Human Assisted Reproductive Technology Act.
The Ministry for the Environment's 2017 Regulatory Stewardship Strategy stated genetic modification had been noted as an area "likely to have significant development in the coming years", and that officials would provide the minister "with advice on appropriate changes to New Zealand's GM policy".
Environment Minister David Parker yesterday said the Government had no plans to change the current law.
NZBIO, the industry organisation representing biotechnology companies, has aired worries about New Zealand being left behind due to its strict regulations.
"Our members and all New Zealanders, through government grants, are participants in the development of products and services that arise from understanding how genes work and how we can use the knowledge to improve health, the environment and our economy," its chief executive Dr Zahra Champion said.
The HSNO Act should be updated, Champion said, "to take account of the past 20 years of understanding about the use of genetic technologies and provide an appropriate balance of risk and benefit for New Zealanders".
But Sustainability Council executive director Simon Terry argued it was in New Zealand's interests to have the use of gene drive governed by strong international regulation, "to guard against a release in another country harming our native biodiversity or agriculture".
"So before considering any local release of a gene drive, we need international governance arrangements in place that are fit for purpose."
The discussion papers and contacts for feedback are available on the society's website.
A further paper with scenarios for the use of gene editing in agriculture will be published soon, along with a paper examining current legislation and regulation.
