The decoded koala genome: a look at the genome should help protect pretty marsupials

is threatening more and more the loss of its habitats.

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They look like plush stuffed animals and are – along with kangaroos – one of Australia's most famous animals: koalas. But the charismatic marsupials are in danger. Their habitats, eucalyptus forests, are more and more destroyed by humans. In addition, among mammals are diseases that threaten populations further.

Endangered Species

"The koala is the only species in the marsupial family that is currently considered threatened," researchers write about Rebecca Johnson at the Australian Museum in Sydney. In order to effectively protect animals, important knowledge about their unique biology is still lacking. Why are koalas so sensitive to certain infections?

The answers to these questions and to others could now give an overview of the genome of the species. Because Johnson and his colleagues first decoded the koala genome. It is the most complete sequencing of a Beutler genome that scientists have succeeded. As the sequencing shows, the koala genome contains 3.4 billion base pairs and 26,000 genes – which is slightly larger than the human genome.

Genes for detoxification

Further badysis of the DNA sequences revealed several abnormalities.Among other things, the research team discovered that some sections of the Beutler genome are repeatedly available in form These gene clusters encode enzymes capable of cleaving toxins and are found in koalas of the liver, but also in other tissues.

"The koala has developed an excellent toolbox for face to the venomous eucalyptus – a box that com Placed many copies of the same tool or a very similar tool, "says co-author Will Nash of the Earlham Institute of Norwich. With this adaptation, Beutler can easily feed his favorite food, which contains beautiful essential oils and many compounds that are toxic to most other animals

Threatening Infections

A look at genetic material also brought Breast milk in these marsupials: "We have identified a number of koala-specific milk proteins that are important for the development of the size of a baby born from beans," says co-author Katherine Belov from the University of Sydney.

These proteins also seem to play an important role in the immune system. They have an antimicrobial effect and are effective against a wide range of fungi and bacteria, including Chlamydia pecorum. "Infections to these bacteria can lead to infertility and blindness and have already severely affected the koala populations of New South Wales and Queensland," says Belov. Information from the genome of the koala can now contribute to the development of drugs

Traces of the virus in the genome

In addition to chlamydia, the koala threatens another pathogen, however: a retrovirus that is not well known. things up to now. In the genome badysis, scientists have discovered that animals carry a number of DNA sequences of these viruses in their genome. Thus, there could be more than a hundred viral presentations in the same koala.

"This information could help us determine which strains of retroviruses are particularly dangerous to animals," says Peter Timms, of Sunshine Coast University. in Maroochydore. "It helps us develop vaccines."

Best possible protection

Overall, researchers put a lot of hope into the now available data, which also provide insights into genetic diversity individual populations. "This work will mark the beginning of a new era for the protection of the iconic koala," says Belov. "The next step will now be to apply our results – in order to preserve this important species," concludes Johnson. (Genetics of Nature, 2018, doi: 10.1038 / s41588-018-0153-5)