NEW funding announced by the New South Wales Government could save Australia’s grain belt from fatal mice infestations.
Professor of Biomedicine at University of Adelaide Dr Paul Thomas will lead a team, in collaboration with the CSIRO and the Centre for Invasive Species Solutions, to undertake breakthrough genetic biocontrol research to target pest populations.
Dr. Thomas said the project will explore two main approaches.
The ‘X-shredder’ approach eliminates sperm containing the X-chromosome, producing more male than female pups.
“The x chromosome gets essentially chopped up into tiny pieces which means that those sperm don’t contribute to fertilizing the egg in the next generation,” Dr. Thomas said.
“Over time you see a population crash because the number of females will eventually reduce further and further because only males are being born at each generation.”
The ‘Female fertility’ approach initially spreads through the population.
Once the modified gene has saturated the population all female offspring will be infertile.
NSW Farmers Association Vice President Xavier Martin says a solution couldn’t come sooner.
“We just can’t keep tearing up money trying to control this, so we won’t plant that paddock, or we won’t plant all those paddocks, or in some cases farmers completely abandoned farms,” he said.
Farmers like Mr Martin have seen first-hand the scourge of vermin ravaging crop fields, where mouse holes have invaded his canola plot southwest of Gunnedah.
“In three nights, they can really do a lot of damage. They can ruin a paddock of emerging canola crops,” he said.
Soon rodent populations grew so large they began to overrun farmsteads and villages in the Liverpool Plains.
“They’re biting us in our beds, they were biting patients in hospitals,” Mr Martin said.
“People were getting infected eyes from mice and leptospirosis you know, blood poisoning.”
“And you know they’re dreadful little dirty mammals that carry every dirty dog thing that affects you and I.”
In May, the NSW government announced a $50m rescue package for the regions which included free poison for farmers and mice bait rebates of $1,000 for small businesses, $500 for households and biocontrol research.
“Best case scenario is that we knock out the mice population completely where they are invasive, but we don’t want in any way to influence the native population of mice,” Dr Thomas said.
People for the Ethical Treatment of Animals (PETA) who traditionally oppose genetic testing on animals have come out in a surprise vote of support for the research.
“No approach is perfect,” the organisation said.
“Biocontrol methods will reduce the countless number of mice suffering in traps and enduring slow, painful deaths from being poisoned, in addition to preventing the poisoning of the species who eat them.”
For Dr Thomas, suppressing the population through natural mating is an ethical alternative in comparison with traditional poisonous baits like zinc phosphide or bromadiolone.
As for Xavier Martin, he says this isn’t the first time that genetic biocontrol research has been proposed in NSW.
“We’ve had quite a bit of money spent on biological research,” he said.
“I’ll call it tens of millions of dollars over the decades, so farmers have seen major projects with a lot of money and so they’re a little bit wary that, you know, is there a biological solution.”
However, for long-term farmers in the region, a plague of the current magnitude has not been seen since the early 1980s.
“The last really major one in New South Wales that was absolutely out of control was back in autumn ’84,” Mr Martin said.
“Mice just overran towns and villages and houses, and the roads just turned to fur; you know, you couldn’t see the bitumen on the road because there were that many mice carcasses.”
“As they darted backwards and forwards they were getting run over by cars and trucks and the road, the pelts of the mice just literally carpeted the roads with fur.”
The complexity and length of research involved must comply with regulations from a biosafety committee accredited by the Office of the Gene Technology Regulator.
Dr Thomas says it is important “to engage the regulator around what kind of field trials we’d be able to do.”
“We’d have to write a safety switch incorporated into those field trials and there’d be social and stakeholder engagements that would go along with that process as well, because it’s a pretty new technology so we want to bring the public along.”
For Mr Martin, the important thing is that it works, and that means trusting in the new research.
“We trust good science; we make a living out of healthy plants and healthy animals and that relies on good science.”