It’s been decades since Australia’s thylacine, known as the Tasmanian tiger, was declared extinct and scientists say they’ve made a breakthrough in researching ways to bring back the carnivore.
Colossal Biosciences, in a press release issued Thursday, said its reconstructed thylacine genome is about 99.9% complete, with 45 gaps that they will work to fill with additional sequencing in the coming months. The company also isolated long RNA molecules from a 110-year-old preserved head, which was skinned and preserved in ethanol.
“The thylacine samples used for our new reference genome are some of the best preserved ancient specimens my team has worked with,” said Beth Shapiro, scientific director of Colossal and director of the Paleogenomics Laboratory at UCSC, where the samples were processed. “It is rare to have a sample that can push the limits of old DNA methods to this extent.”
Efforts to bring back the Tasmanian tiger
Preserving a complete Tasmanian tiger head allowed scientists to study RNA samples from several important tissue areas, including the tongue, nasal cavity, brain and eyes. This will allow researchers to determine what a thylacine tastes and smells like, as well as its vision type and how its brain functions, according to Andrew Park, a member of Colossal’s scientific advisory board and a researcher at the University’s TIGRR lab. from Melbourne. .
“We are getting closer every day to being able to reintegrate the thylacine into the ecosystem, which of course is also a major conservation benefit,” Pask said.
Pask, speaking with 60 minutes Earlier this year, researchers said they were working with the Tasmanian tiger’s closest living relative – a small marsupial called the fat-tailed dunnart – to bring the animal back.
“But this little dunnart is a fierce carnivore, even though it’s very, very small,” Pask said. “And it’s a really good substitute for us to be able to do all that editing.”
Scientists compared the DNA of dunnart and thylacine, Pask told 60 Minutes. From there, it’s a matter of going in and modifying the DNA to turn a fat-tailed Dunnart cell into a thylacine cell.
Colossal Biosciences said Thursday it engineered more than 300 unique genetic changes into a Dunnart cell, making it “the most engineered animal cell to date.”
“We’re really pushing the frontiers of de-extinction technologies,” Pask said, “from innovative methods for finding the regions of the genome that drive evolution to new methods for determining gene function. We’re in the best place ever to reconstruct this species using the most comprehensive genomic resources and best-informed experiments to determine function.”
Efforts to revive the Tasmanian tiger are not limited to Australia. Last year, scientists RNA recovered and sequenced from a 130-year-old Tasmanian tiger specimen preserved at room temperature at the Natural History Museum of Sweden.
How the Tasmanian Tiger Died
Thylacines have roamed Tasmania for thousands of years. Despite the nickname Tasmanian tiger, carnivores were marsupials, like kangaroos, koalas and Tasmanian devils.
In the late 1800s, the local government paid bounties to hunters showing Tasmanian tiger carcasses because the animals ate farmers’ sheep, 60 Minutes previously reported. By the mid-1930s, the Tasmanian tiger population was reduced to a single thylacine at Beaumaris Zoo in Hobart, Tasmania’s capital. He died there in 1936.
Australia has also authorized the culling of kangaroos, approving the death of thousands of kangaroos over the years. Authorities said the kangaroo population was feeding on grassy habitats of endangered species. Authorities have also warned in the past that there is not enough food available to feed large populations of kangaroos.
