Lee Skerratt: Saving species with a 2019 ARC Future Fellowship

Associate Professor Lee Skerratt has been awarded a 2019 Australian Research Council (ARC) Future Fellowship that will aid his biotechnology research into disease immunity. The research aims to save dwindling frog populations while proving the value of synthetic biology in restoring threatened wildlife populations.

The fungus Batrachochytrium dendrobatidis invades and eats away at the skin of frogs and other amphibians, disrupting their ability to absorb nutrients and causing fatal heart attacks. This infection is known as chytridiomycosis.

Chytridiomycosis is responsible for dramatic population declines in 501 species of amphibians, including 90 extinctions, according to a 2019 Science publication by Associate Professor Skerratt, Australian National University researcher Dr Ben Scheele, and a global network of researchers, including Associate Professor Lee Berger, who discovered the disease.

“Chytridiomycosis is the major threat and many species will disappear unless we develop a targeted sustainable solution,” Associate Professor Skerratt said at the time.

Now, he will seek to develop that solution by applying advanced synthetic biology methods to identify and improve frogs’ immunity to the disease, thanks to an ARC Future Fellowship.

The Fellowship will fund his synthetic biology research in the Melbourne Veterinary School’s One Health Research Group for four years and will include training for four PhD and two Masters graduate researchers in synthetic biology, genomics, transgenics and wildlife health.

Lee Skerratt
Associate Professor Lee Skerratt, Principal Research Fellow (Wildlife Bioscecurity).

Associate Professors Skerratt and Berger lead the group, which is based at the University of Melbourne’s Werribee campus. Its members investigate the causes and control of infectious diseases that impact biodiversity.

Synthetic biology is a new, cross-disciplinary approach that draws from engineering to identify or design and fabricate DNA sequences that can be inserted into the genes of existing species.

Associate Professor Skerratt and the graduate researchers funded by the Fellowship will identify corroboree frog genes associated with protective immunity to chytridiomycosis, insert these candidate genes into vulnerable frogs using transgenesis and CRISPR technology and assess the effectiveness of the inserted genes at protecting frogs from the disease.

This approach offers distinct advantages over traditional methods of selective breeding, such as having a much shorter time frame, being readily transferable across species and having a lower risk of selecting against other favourable traits.

The project will be the first to apply transgenesis to wildlife conservation. Associate Professor Skerratt says it will make Australia a world leader in wildlife conservation by providing an entirely new model for saving species threatened by diseases.

“This research will transform our ability to control wildlife diseases and is feasible due to recent advances in synthetic biology,” he says.

“We will also determine how synthetic biology can provide better management and restoration of our environment.”

Drastic threat from disease requires an unconventional approach

This may sound like a radical step, but Associate Professor Skerratt, who has researched biodiversity conservation since the 1990s and witnessed the decline and loss of many species to chytridiomycosis, says the nature and scale of the destruction B. dendrobatidis has caused necessitates unconventional solutions.

“Once B. dendrobatidis enters a country it spreads quickly and causes massive declines and extinctions in susceptible species. Although it’s too late for B. dendrobatidis, national biosecurity is essential to help mitigate the spread of other invasive wildlife diseases. For those that do spread and for B. dendrobatidis, we need solutions to combat their impact,” he says.

“We need innovation to provide the required solutions, such as helping species to evolve resistance more quickly, if we are to fight the effects of globalisation and the consequent spread of virulent pathogens.”

One target for the research will be the critically endangered and iconic Australian corroboree frog of the Southern Tablelands in New South Wales, with its distinct bright yellow and black skin pattern.

A corroboree frog at Healesville Sanctuary in Victoria.
A corroboree frog at Healesville Sanctuary in Victoria. Photo: mcdexx, Flickr.

It is classified as critically endangered and, with fewer than 200 individuals left in the wild, it is among the species most at-risk of extinction in Australia.

While human intrusion on its environment, drought and introduced predators have contributed to the corroboree frog’s decline, Associate Professor Skerratt says chytridiomycosis is “by far” the main threat to it and many other amphibian species’ survival.

Half of all amphibian species are at risk of extinction, and Australia spends millions of dollars each year maintaining captive assurance colonies of wildlife, including the corroboree frog. Reducing the burden chytridiomycosis places on wildlife health could increase resources available for other threatened species, making the potential benefits of this research extend beyond wildlife health, says Associate Professor Skerratt.

“Studying wildlife health also provides insights into health generally, which can be used directly to advance our health and that of our domestic animals,” he says.

“By improving wildlife health we reduce the risk of disease spilling over into humans and domesticated animals and we improve the environment we depend on. This is the One Health approach, which recognises that our health and the health of our animals is inextricably linked to wildlife health and the environment.”

Success in this project could therefore not only lead to restored amphibian populations, but also to further effective, streamlined and inexpensive methods for fighting emerging diseases worldwide.

Professor Anna Meredith, Head of the Melbourne Veterinary School, says the Fellowship is a major boost to the School’s initiative to establish a critical mass of expertise in wildlife health research and research training, as well as to the Faculty's One Health approach to research.

“As a conservation health researcher myself, it’s clear chytridiomycosis is an enormous and intractable threat to our planet’s biodiversity, and that new and innovative approaches will be needed to address it,” she says.

“This is a very promising application of the latest research approaches to an urgent problem, and very much in line with our School and Faculty’s One Health mission. It will also add to our – and Australia’s – excellence in biotechnology and conservation, and train future wildlife health scientists in finding new ways to help resolve the global biodiversity crisis.”

“Congratulations on this excellent result, Lee!”

Banner image: A Corroboree frog. Photo: Zichen Wang, Flickr.