Scientists Plan Gene Attack To Render Cane Toads Hopless
The Age
Monday December 4, 2000
SCIENCE REPORTER
Since cane toads were released in Australia in 1935 they have withstood all attempts to bump them off.
Finding a natural predator failed. Distracting them with sex hormones didn't work. Even cane toad cricket - where toads were substituted for cricket balls - couldn't halt the amphibian's relentless march into new territory.
Now scientists are giving gene technology a go. The Federal Government has given the CSIRO $1million to exploit the toad's DNA and, it is hoped, control the warty wanderers.
Announcing the funding, Environment Minister Robert Hill said cane toads continued to threaten native species.
Researchers at the CSIRO's division of sustainable ecosystems in Canberra are searching for a gene that is critical to cane toad development and can be switched off, thereby stopping tadpoles from becoming toads.
Cane toads were introduced at Gordonvale in North Queensland to control the greybacked cane beetle. They have spread into New South Wales and the Northern Territory. It is feared they may soon hop into the wetlands of Kakadu National Park.
While scientists in Canberra search for the development-controlling gene, researchers at the Australian Animal Health Laboratory in Geelong are perfecting viruses that can infect cane toad tadpoles. Alex Hyatt, a scientist at the laboratory, said the viruses would be weakened so other amphibians and fish would not suffer the effects of the virus if they became infected.
``In Canberra they are trying to identify a gene associated with the critical stages of metamorphosis and then identify if this gene can be changed to interfere with metamorphosis," Dr Hyatt said.
``In Geelong we're investigating what viruses can be used in the environment and how they can be modified so they're safe to release but at the same time target the cane toad," he said.
Once the the development controlling gene was found it would be inserted into the virus and introduced into cane toad tadpoles, Dr Hyatt said. These tadpoles would not be able to develop into adult toads and would therefore be unable to reproduce.
In time, it was possible waterholes would be ``seeded" with the virus so it spread naturally through waterways, he said.
© 2000 The Age