Sequence the koala genome and a door is opened to save them from disappearing

Scientists from eight countries have sequenced the genome of this marsupial, an effort that will be key in treating their complex diseases and their conservation. Their populations are expected to decline by up to 50% in the next 20 years.

The Koala (Phascolarctos cinereus) is an iconic species of Australia recognized worldwide. Because of its unique biological character, it is of interest to scientists, governments and the public alike. However, there are fewer and fewer. According to the experts, s expects that koala populations will decline throughout Australia up to 50% in the next three generations (twenty years or so). (Read They Get the First Image of a "Newborn" Planet)

The Koalas are unique pieces in the history of evolution. They are the only living representatives of the marsupial family of fascolárctidos. They can eat poisonous eucalyptus leaves that would kill most mammals. The threats of predation and the loss of habitat due to urbanization make them particularly vulnerable. They are threatened by disease, low genetic diversity and climate change. (Read Here's How Testicles came to your site according to science)

A Team of Scientists led by the Research Institute of the Australian Museum and the University of Sydney (Australia ), sequenced the koala genome using long reading technology and optical mapping. "The genome provides a stepping stone for the conservation of this biologically unique species," says Katherine Belov, co-author of the University of Sydney and professor of comparative genomics.

The work revealed an expansion of gene families linked to detoxifying enzymes, which allow koalas to feed on eucalyptus leaves rich in phenolic compounds.

These genes have been expressed in many koala tissues, especially in the liver, indicating that they play a very important role in detoxification. It is likely that koalas have become specialists in the koala. ;food. As Rebecca Johnson, director of the Australian Museum's Research Institute, explains, "this allowed them to find their subsistence niche to survive since they could count on a less competitive food source for them." other species that could not detoxify as effectively.

In addition, identified groups of genes related to the immune system that will improve the study of Chlamydia infection, common among koalas populations . "The Koala Genome Consortium has been an ambitious journey that gives us a good understanding of the genetic components that make up this animal, one of the most charismatic and iconic mammals in Australia and the world," says Johnson .

Genomics to conserve the species

The consortium is led by Australian scientists and seven other countries and has 29 institutions. A total of more than 3.4 billion base pairs and more than 26,000 genes were sequenced from the koala genome.

Australia has the highest extinction rate of mammals compared to any other country in the world. . The number of koalas has dropped in the north since European colonization, but has increased in some parts of the south, particularly in Victoria and southern Australia. The uneven response of koala populations throughout their range is one of the greatest challenges of large scale management of the species.

The genome was sequenced at the Ramaciotti Genomics Center of the University. of New South Wales, using a new sequencing technology. "Then, we badembled the genome with supercomputers, which allowed the Consortium to study more than 20,000 genes of this unique species," says Marc Wilkins, director of the Ramaciotti Center.

Secrets of milk

Another important discovery was the characterization of the composition of koala milk. Like all marsupials, koalas spend most of their development in a bag. They are born without an immune system after 34 to 36 days of gestation and spend about six months developing in the bag.

"We characterize the major components of bad milk, which is crucial for koala newborns, born to the size of a bean and weighing half a gram," says Belov. "We identify the genes that allow the koala to adjust the composition of the milk protein throughout the stages of lactation, to meet the changing needs of their offspring. "

Chlamydia and retroviruses attack koalas [19659003] Koala populations in New South Wales and Queensland have been affected by chlamydia, a disease that causes infertility and blindness.Using information from the koala genome, scientists hope to A vaccine to fight this disease and other diseases.

"In addition to chlamydia, koala retrovirus (KoRV) is another major kalaal infection." The complete genome is fundamental to showinghow a single koala can have more than a hundred KoRV insertions in its genome, including many versions of KoRV, "says Professor Peter Timms of the Sunshine Coast University. "This information will allow us to determine which strains of KoRV are the most dangerous and help in the development of a KoRV vaccine," he concludes.

All sequencing data generated by the Koala Genome Consortium has been deposited in public databases. They have been made freely available to scientists around the world. "Open information maximizes the benefits that koala populations and the public derive from research," says Johnson.