Media Releases
Koala genome reveals its secret
It has long been thought that low levels of koala genetic diversity is a reason for their declining populations and local extinctions, but James Cook University and Sydney University researchers have found this is not the case.
Photo: Monal Lal
For the
first time, the genome of the koala (Phascolarctos cinereus) has been
studied across the species range. Previous research has shown that many
marsupials have low genetic diversity – often a sign of inbreeding and
mating with kin, which is not unusual in animals with declining
populations.
A new study by researchers at JCU and the
University of Sydney, in partnership with the NGO Science for Wildlife
organisation and San Diego Zoo, has used cutting-edge genetic technology
to answer critical questions about koala conservation.
In the
ground-breaking study, the group has applied whole-genome DNA sequencing
to show that koalas still maintain higher levels of genetic diversity
than originally thought.
JCU’s Associate Professor Kyall Zenger
said the finding was very exciting, given that koala numbers have been
declining to the point where they have been listed as being at risk of
becoming endangered.
“To effectively manage koalas across
Australia and in captivity we must understand how genetically diverse
these populations are – how ‘fit’ they are,” he said.
Shannon
Kjeldsen, a PhD student working on the project at JCU, said her research
also showed that there is very little evidence for the three currently
recognised subspecies of koalas.
“It’s widely thought that there
are three distinct subspecies of koala inhabiting Southern and Northern
Australia, respectively,” she said.
Northern koalas have been
known to be smaller and lighter in colour than their southern
counterparts, which are larger, darker and have thicker fur.
“We
know that it would be unwise to move koalas between these regions,
because they live in different climates and have adapted to different
environments, but we do not know where the management boundaries lie,”
Ms Kjeldsen said.
The duo is working alongside Professor Herman
Raadsma from Sydney University, Dr Kellie Leigh from Science for
Wildlife, and Ms Jennifer Tobey from the San Diego Institute for
Conservation Research.
Associate Professor Zenger said management
and implementation of a national koala conservation program was vitally
important to protect this charismatic species.
“Until now there has been a lack of species-wide information to help coordinate conservation efforts,” he said.
“These
results have shown the genetic diversity of the koalas sampled from all
key locations on the east coast of Australia is far from being inbred,
and actually is as diverse as many other wild species.”
Science
for Wildlife Inc Director, Dr Kellie Leigh said: “This development is
extremely exciting, in that it offers a tool to understand how all koala
populations are genetically linked.”
The tool also offers exciting possibilities to better manage captive breeding populations.
Ms
Tobey said: “The Australian research gives for the first time a clear
view on how captive populations can be mapped to the national koala
population, and to manage breeding to maximise genetic diversity.”
This
project is funded and supported by an Australian Research Council (ARC)
Linkage Project grant, with industry funding and in-kind support from
partners San Diego Zoo Koala Education & Conservation Program and
James Cook University, Sydney University, and Science for Wildlife.
Caroline Kaurila, JCU Media Liaison, 0437 028 175