Genetic research has revealed that the endangered Australian native bilby – with its ridiculously oversized ears and elongated snout – doesn’t just look strange on the outside.
“Bilbies are weird and cool. The genome was fascinating,” says Prof Carolyn Hogg, from the University of Sydney, who led research that sequenced the larger bilby’s genome for the first time.
“They have the largest genome of any marsupial – it has 3.66 billion pieces,” Hogg, of the Australasian Game Genomics Group, said.
The genetic sequence will help conservationists direct their efforts to save the species, which has already disappeared from about 80% of its range, Hogg said.
The reason the bilby’s genome is so large may be due in part to how it evolved its incredible sense of smell.
“Because they dig in the desert looking for roots and seeds, they are very important to the landscape and circulate the soil,” Hogg said.
Published on Monday in the journal Nature Ecology and EvolutionThe research is the result of work to sequence the genome that began in 2018 but was put on hold due to the global pandemic.
The genetic blueprint of the bilby, a culturally important species for many indigenous communities, includes information about how the elusive nocturnal omnivore grows and develops.
Hogg said: “This helps us understand what gives bilbies their unique sense of smell and how they survive in the desert without drinking water.”
All 115 genes expressed in the human uterus to produce a placenta are also found in the bilby, Hogg said. “They have so many fascinating genes.”
The European invasion and subsequent spread of feral cats, foxes and rabbits – the latter competing for food with bilbies – caused bilby numbers to decline.
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The only other member of the bilby marsupial family – the lesser bilby – is extinct and is thought to have hung around the landscape until the 1960s. The team also sequenced the lesser bilby using a scraping of the skull of a specimen collected in 1898.
Greater bilby numbers in the wild are not known, but around 6,000 live in sanctuaries that are either fenced off for protection or located on islands.
The genome is already being used to help manage bilbies in zoos, fenced sanctuaries and islands.
Hogg said: “By selecting individuals for translocation and release, we maximize their genetic diversity and therefore improve the population’s ability to adapt to a changing world.”
A method to track and evaluate bilby populations with their smears has also been boosted by genome sequencing, enabling a more precise way to understand what is happening to wild populations.
Ranger Scott West, from the Kiwirrkurra Indigenous Protected Area in Western Australia, said: “We know a lot about bilbies – where they live, what they eat and how to track them.
“It’s good to use iPads for mapping and cameras to monitor it. The DNA work also helps to check if bilbies are related, where they come from and how far they have travelled.”
