Koalas eating their forests to extinction with aid of ‘detox kit’
KOALAS are at risk of destroying their own habitat because they have a unique detox kit which allows them to eat poisonous eucalyptus.
Scientists have found that the marsupials are able to specialise in eating the poisonous plant because they have large numbers of genes active in the liver devoted to detoxification.
This has long given them the advantage of eating the plant which is avoided by their competitors, but it has also left them vulnerable to the loss of their forest habitat.
The discovery was made by a team of 54 researchers who put together a complete genetic blueprint and sequenced more than 3.4billion “letters” making up the koala genetic code.
They were also able to identify more than 26,000 genes – stretches of DNA that provide the instructions for making proteins – and unravelled some of their functions.
The key discovery, published in the latest issue of the journal Nature Genetics, showed that koala genes produce a range of cytochrome P450 enzymes that break down poisonous compounds. They are what enable the koala to live on a diet of highly toxic eucalyptus leaves, the scientists believe.
Team leader Professor Rebecca Johnson, director of the Australian Museum Research Institute in Sydney, said: “This probably helped them to find their niche to survive, as they could rely on a food source that would have less competition from other species who were not able to detoxify as effectively.”
Her British colleague Dr Will Nash, from the Earlham Institute in Norwich, added: “The koala has evolved an excellent toolkit to deal with eating highly toxic eucalyptus, one made up of lots of copies of the same, or very similar, tools.”
The animal is classified as “vulnerable” due to habitat loss and disease. Chlamydia and koala retrovirus have severely impacted populations in New South Wales and Queensland.