UQ researchers Dr Karishma Mody, left, and Yunjia Yang with a wool sample. Image – Megan Pope, UQ.

A CHEMICAL-FREE method of controlling flystrike in sheep with the potential to reduce or eliminate the need for mulesing or combat cattle ticks and buffalo fly is a step closer, according to University of Queensland research.

Queensland Alliance for Agriculture and Food Innovation research fellow Dr Karishma Mody and PhD candidate Yunjia Yang are using innovative RNA technology to combat sheep blowfly, a major disease and welfare issue for sheep.

RNA interference has the potential to control flystrike by regulating the pest’s growth and development.

Dr Mody said RNAi technology is a natural mechanism and it is target specific.

“By targeting essential genes of sheep blowfly, certainly there is a potential to reduce or eliminate the need for mulesing,” she said.

Dr Mody said RNAi is a different research approach to the CSIRO’s flystrike vaccine development.

“With the innovative RNAi we are focusing on the essential genes and targeting them in blowfly’s life cycle.

“We are focused on developing sustainable solution for animal agriculture,” she said.

“Our promising research is in early stages and more work needs to be conducted to contribute towards the translation of the technology.”

Dr Mody said there is also potential for this method to be used on other pest problems in livestock, including cattle ticks and buffalo fly in cattle.

“The other positive is that this proposed method is sustainable, non-toxic and has minimal associated resistance issues.”

Dr Mody said it costs nearly $280 million dollars a year in labour and chemical treatments to keep flystrike under control in Australia.

“When introduced to the sheep blowfly diet, these sustainable double stranded RNA (dsRNA) molecules we’ve designed affect the way the insect grows.”

Genes being targeted to slow or stop fly growth

Dr Karishma Mody and Yunjia Yang checking a sample. Image – Megan Pope, UQ

Dr Mody said the next challenge was to identify target genes that can be silenced by the dsRNA to slow insect growth and potentially kill the blowfly.

“Three of the 12 genes screened gave promising results,” she said.

“We have established that RNA inference (RNAi) has the potential to control pests which affect livestock by regulating the pest’s growth and development.

“The idea came through my work with Professor Neena Mitter who focuses on RNAi-based bio-insecticides to control crop pests and pathogens,” Dr Mody said.

“Along with Professor Tim Mahony, we began to explore whether we can use the same approach for animal health.”

However, Dr Mody said they had identified challenges that warrant further research.

“dsRNA can easily degrade because of the diet of sheep blowfly, so we are working on particle-based delivery platforms to help improve its stability for real world application,” she said.

“Australia is one of the world’s leading wool producers, so it’s fitting that we lead the way with innovative research to develop better control measures for pests.

Dr Mody said UQ does have some ongoing funds to support its research work and is simultaneously also looking for more opportunities.

“We are highly motivated to deliver outcomes in partnership with industry to ensure the translation of the established proof-of-concept research.”

The research was published in Pest Management Science.