Cane toad DNA breakthrough 'may help stop' toxic pest

Cane toads are highly adaptive and release a destructive toxin

Scientists say they have unlocked the DNA blueprint of the cane toad, raising fresh hopes of slowing the animal's destruction of habitats.

The amphibian, native to South America, has become a prolific pest since it was introduced in other parts of the world last century.

In Australia, it has spread rapidly and had a deadly impact on native wildlife.

Researchers say the draft genome could be a crucial step in efforts to halt the animal's march.

"Sequencing the genome is the quantum leap that means we can understand it better and start to do lots of other things around its control," said emeritus Prof Rick Shine, a study co-author from the University of Sydney.

The international team of researchers said the discovery would offer biological clues about the animal's evolution.

• How the cane toad has spread in Australia

• Scientists train lizards to not eat toxic toads

The study used advanced computers to sequence 360 billion DNA pairs and construct the "genome jigsaw". More than 90% of the cane toad's genes were found, they said.

Invasive threat

Cane toads are highly adaptable and can be found in more than 130 countries, the researchers said.

Since being introduced to Australia in 1935 to control a sugarcane beetle, the species has spread rapidly across the nation.

Scientists says cane toads are evolving rapidly

Cane toads threaten many larger species - such as snakes, lizards and even crocodiles - which ingest the amphibian's deadly toxin.

"It is a very adaptable and invasive animal - it came from a wet jungle and was able to hop across arid desert in northern Australia," Prof Peter White, from the University of New South Wales, told the BBC.

"That shows you the capability it has to evolve to the environment."

With a genome in place, it will be easier and cheaper to track evolutionary changes in other cane toads, Prof White said.

Control hopes

Prof White said they had also discovered three new viruses within the DNA which could be used as "bio-controls". Such methods have been successful in controlling rabbit populations.

However, further research was required to determine whether the viruses could harm other species.

"There's a lot more work to be done. However, this research is the first - but most important - step in finding an effective way to control the cane toad," Prof White said.

Scientists from Australia, Portugal and Brazil worked on the project. The findings have been published in GigaScience journal.