【Dear Utol (2025): Binyag Episode 43】

Koalas,Dear Utol (2025): Binyag Episode 43 the tree-dwelling marsupials found in eucalyptus forests and woodlands across Eastern Australia, is not just a cute and fluffy fascination for tourists.

It's also a perfect research subject for a group of dedicated scientists working to ensure the animal's survival.

Publishing their findings in the journal Nature Genetics, a group of 54 scientists from seven countries successfully sequenced over 26,000 genes in the koala genome, assembling it with supercomputers.

Why would you spend time decoding a genomic sequence when you have so much Netflix to watch? Survival, man.

“This milestone has come from our vision to use genomics to conserve this species," Rebecca Johnson, who lead the research, said in a press statement.

"The genetic blueprint has not only unearthed a wealth of data regarding the koala’s unusual and highly specialised diet of eucalyptus leaves, but also provides important insights into their immune system, population diversity and the evolution of koalas."

Cracking the genetic code grants new access into a koala's unique biology, or the species' "genetic building blocks" as Johnson calls them. The high accuracy of this data gives scientists new information that will help to pinpoint conservation efforts and more effectively aid in disease treatment.

“Because of its high quality, this genome is now a fundamental resource for all the other marsupial genomes which have yet to be generated and studied. We will be able to use this as a reference for the entire marsupial community," said Professor Marc Wilkins, director of the Ramaciotti Centre for Genomics at the University of New South Wales, where the base pairs were sequenced. 

Here's what they found out:

Koala milk builds immunity and could be used to treat chlamydia

Akin to marsupials like kangaroos, possums, and wallabies, koalas spend their early development in the warm, cushy confines of the pouch. Koalas are born without an immune system, and thanks to the decoded genome, the team was able to figure out that koala milk plays an important role in building this immunity.

It also looks like playtpus milk isn't the only one that has defensive properties. Koala milk proteins may be one of the creature's best defences against chlamydia — a common disease in koalas, causing blindness and infertility in members of the species in large numbers across the states of New South Wales and Queensland.

"These proteins may have an antimicrobial role, showing activity against a range of bacterial and fungal species, including chlamydia pecorum, the strain known to cause ocular and reproductive disease in koalas,” University of Sydney's Professor Katherine Belov said in a statement.

Now that they've discovered these koala milk properties, scientists could potentially develop a vaccine for diseases like this. And it could be a game-changer.

Why koalas can eat toxic eucalyptus leaves

Koalas almost exclusively eat the leaves of eucalyptus trees. It's a low calorie diet, so koalas snooze up to 22 hours a day, and they experience very little competition for this food source.

This diet would likely be toxic or fatal to most other animals. So, how do koalas manage?

They have several rather enviable mechanisms to detoxify the eucalyptus within their liver, and expansions in their smell and taste receptors allow koalas to be super picky about which leaves they're eating.

All this knowledge comes from the genome, which can give scientists a good sense of what's going on inside the koalas without an invasive tissue sample.

Genetic diversity is a problem worth monitoring

According to the research team, one of the biggest threats to koalas is human-driven habitat loss, thanks to a cheeky huge amount of of land clearing and urbanisation.

In fact, according to the paper, the koala is the onlymember of the marsupial family Phascolarctidae classified as ‘vulnerable’ under Australia’s Environment Protection and Biodiversity Conservation Act 1999, and that's purely thanks to human activity. Great.

On that land clearing issue, once multiple habitats become disconnected for the long-term, you're upping the chances of koala inbreeding, so genetic diversity is reduced. And that's not good for any species.

According to the paper, low genetic diversity in koalas has been associated with genetic abnormalities, which is problematic for the future health of the species.

So, what's happening with all this data?

Every last bit of the sequence generated by The Koala Genome Consortium has been dropped into public databases, and is freely available for scientists to pick up, analyse and implement.

“Our next efforts must be in the application of these findings to genetically manage koala populations and advance the treatment of the diseases affecting koalas, with the goal of conserving this very important species,” said Johnson.

Koalas, consider yourself analysed and ready for protection. You can go back to sleep now.