Marsupial invader
 |
Rachael Tarlinton, a PhD student from the School of Molecular and Microbial Sciences, and her supervisors Associate Professor Paul Young and Dr Joanne Meers, have found the genome of the koala is being invaded by the koala retrovirus (KoRV).
The researchers studied the presence of the virus in captive and wild koala populations.
Retroviruses are a group of viruses that insert a DNA copy of their genome into the chromosomes of a host cell as part of their natural life cycle. Some retroviruses become permanently integrated into the host genome and are passed on from one generation to the next, gradually being inactivated so they no longer produce harmful infections.
These endogenous retroviruses are widespread in animals, with most having invaded their hosts thousands to millions of years ago.
KoRV is an active virus that appears to have entered the koala genome as recently as 100 to 200 years ago.
Unlike endogenous retroviruses of other species that were fairly stable and ancient inserts in the host genome of all members of the species, some koala populations had been either free of KoRV, or showed a mixed prevalence, Dr Young said. This, combined with high levels of viral activity and variability between individual koalas, suggested the virus was in transition between infectious and endogenous forms, he said.
