Bilby future enhanced with completion of first full genome map

Researchers have sequenced the entire genome of Australia’s greater bilby for the first time which they say will improve conservation efforts for the threatened species.

The greater bilby (Macrotis lagotis) is a marsupial native to Australia. Because of its rabbit-like long ears, it is sometimes referred to as Australia’s ‘Easter bunny.” The nocturnal omnivore lives in burrows in Australia’s deserts. Adults can reach more than 50cm in length and weigh more than 2kg.

Bilbies were once found across 70% of the continent, but today they’re restricted to about 20% of their former range. Now, they can be found in the deserts of the Northern Territory and Western Australia, and a small population exists in southwest Queensland.

Map of australia bilby distribution in red
Map of bilby distribution across Australia. Credit: Nrg800 via Wikimedia Commons (CC BY-SA 3.0).

Since the lesser bilby went extinct in the 1960s, the greater bilby is the only remaining species of bilby. It is estimated that the population of greater bilbies is fewer than 10,000. It is listed as “vulnerable” on the IUCN red list.

The marsupials have been in decline since the arrival of Europeans on the continent and the introduction of cats, foxes and rabbits which compete with bilbies for food.

A team led by researchers at the University of Sydney used DNA from a dead bilby from a zoo, to sequence the genome of the greater bilby. They also created the first genome of the lesser bilby from a skull collected in 1898.

The research is detailed in a paper published in the journal Nature Ecology & Evolution.

“The greater bilby reference genome is one of the highest quality marsupial genomes to date, presented as nine pieces, representing each of the bilby chromosomes,” says lead author Professor Carolyn Hogg from the university’s Australasian Wildlife Genomics Group. “It offers insights into biology, evolution and population management.”

A reference genome is like having a puzzle box lid which is a guide to knowing what all the DNA puzzle pieces mean and how they fit together.

“It helps us understand what gives bilbies their unique sense of smell and how they survive in the desert without drinking water,” Hogg adds. “Everything takes 4 times longer and is 4 times more difficult when you don’t have a reference genome. We have accelerated science to ensure the ongoing survival of bilbies.”

The genome can be used to manage bilby populations in zoos, fenced sanctuaries and islands.

“By selecting individuals for translocation and release we maximise their genetic diversity, thus improving the population’s ability to adapt to a changing world,” Hogg explains.

Having the genome will also help develop more precise scat testing methods to complement existing traditional practices used by Indigenous rangers.

“We know a lot about bilbies – where they live, what they eat, and how to track them,” says ranger Scott West from the Kiwirrkurra Indigenous Protected Area in Western Australia.

“It’s good to use iPads for mapping, and cameras to monitor them. The DNA work also helps check if bilbies are related, where they are from and how far they travelled. Using old ways and new ways together helps us get good information about bilbies and how to look after them. This is what two-way science is.”

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