GEIS-新闻详情

Australian scientists uncover how koala virus transmits to offspring

2021-09-07 00:00:00.0 海峡时报-亚洲原网页

SYDNEY (XINHUA) - Scientists from Australia's University of Queensland (UQ) have discovered a deadly koala disease's ability to transfer between parents and their offspring, uncovering a new dimension of the threat to this iconic Australian marsupial, according to a research unveiled on Tuesday (Sept 7).

Associate Professor Keith Chappell, from UQ's School of Chemistry and Molecular Biosciences, said the virus, known as Koala retrovirus (KoRV), exposes koala's immune systems to a variety of diseases, including cancer and chlamydia.

"The virus causes immune depletion, likely making it much harder for koalas to cope with these other, already-detrimental environmental stressors... like climate change and habitat loss," said Prof Chappell.

The discovery, published in the Proceedings of the National Academy of Sciences, was made after the scientists sequenced variations of the virus DNA in 109 koalas - "we finally revealed how the virus spreads - from mother to joey".

The virus can be particularly devastating to koala populations as the exposure to chlamydia can render females infertile, and cause bladder and eye problems that add to the difficulties of foraging for food and avoiding predators.

A 2017 study also from the university found that koala populations in certain areas of Queensland had been reduced by about 80 per cent from 1997 to 2013.

One of the leading causes of death that resulted in this sharp decline in population was the spread of disease, and in particular, chlamydia.

Lead author and PhD candidate Briony Joyce said the research will "pave the way for evidence-based conservation" and could lead to a rethinking of the way koala conservation is done in Australia.

Its scope will have particular relevance in the Australian states of New South Wales and Queensland where koalas are most impacted by disease.

"This work will be highly informative for koala conservation, as it suggests that captive breeding programmes focused on mothers that have a low amount of retrovirus variants, could result in healthier animals for release," said Ms Joyce.

She also proposed treating populations in the wild to reduce the rate of transmission to new generations. "Also, we propose that antiretroviral treatment - if shown to be safe in koala and effective against KoRV - could be used specifically in mothers during breeding seasons to prevent transmission. We must do everything we can to ensure the survival of this culturally important species."