forAchievements sometimes appear in unexpected places. Researchers working on the international campaign to bring back the Tasmanian tiger say they found it in a long-ignored bucket at the back of a cupboard at the Melbourne Museum.
It contained the surprisingly well-preserved head of the extinct marsupial, also known as the Tasmanian tiger.
Professor Andrew Pask, head of the Tasmanian Tiger Integrated Genetics Centre, said: “It was literally a head in a bucket of ethanol in the back of a cupboard that had just been thrown out with all the skin removed, and it had been there for about 110 years.” says the Restoration Research Laboratory (with the perfect abbreviation Tigrr) at the University of Melbourne.
“It was a very depraved sight, absolutely horrific. People cut huge pieces of it off.
Aesthetics aside, the sample had a lot going for it. It contained materials that scientists thought were impossible to find, including long RNA molecules that are essential for reconstructing the genome of an extinct animal. “This was a miracle that happened to this sample,” he says. “It blew my mind.”
A year later, Pask says he has contributed more to the work of the team of Australian and American scientists trying to revive the species than he expected at this stage. “We’ve come further than I thought we would, and we’ve completed a lot of things that we thought would be very difficult and others said were impossible,” he says.
Plan to “remove” thymic tigers
The Tasmanian tiger restoration project is managed by Colossal, a Texas-based biotechnology company that works to “de-extinction and species conservation,” and also aims to recreate the woolly mammoth and dodo using genetic engineering techniques.
Led by technology and software entrepreneur Ben Lamm, Colossal has raised $235 million, directly employs 155 people, and funds research in 13 laboratories around the world. They include the Tigrr Laboratory, which operates at the University of Melbourne’s School of Biological Sciences.
The thylacine was Australia’s only predatory animal. They once lived all over the continent, but were restricted to Tasmania about 3,000 years ago. It was dog-like in appearance with stripes on its back, and was widely hunted after European colonization. The last known survivor died in captivity in 1936 and was officially declared extinct in the 1980s.
Colossal says researchers have made several breakthroughs in their work on the species, bringing the company much closer to its goal of returning the species to the wild in Tasmania. It includes what they say is the highest quality ancient genome ever produced, with just 45 gaps in the genetic blueprint containing about 3 billion pieces of information.
Lam says it’s an “amazing scientific leap” that puts the program “on track to eliminate the extinction of the Tasmanian tiger,” while other recent discoveries will be immediately useful in protecting the critically endangered species. “We are pushing as fast as we can to create the science needed to make extinction a thing of the past,” he says.
The soft tissue in the Victoria Museums specimen, which the researchers called the “head in a bucket,” contains long conserved sequences of DNA — genetic material that is roughly the same in every cell nucleus in the body — but also long molecules of RNA. (RNA). The latter was decisive and unexpected, Pask says.
RNA is much less stable than DNA. It varies depending on the types of tissue within the sample and contains what is effectively a readout of active genes needed for a particular tissue to function. This meant that the researchers were able to obtain information regarding the animal’s nose, eyes, tongue and other facial materials, giving a picture of what the thylacine could taste, what it could smell, what kind of vision it had, and how its brain worked.
The result, Pask says, is the first extinct animal genome, which he calls “an amazing blueprint.” “It helps us prove that what we are bringing back is actually a Tasmanian tiger and not a hybrid animal,” he says.
Thylacine researchers aim to take stem cells from a living species with DNA similar to the Tasmanian tiger Fat-tailed donartAnd transform them into the closest possible approximation of thylacine cells using gene editing expertise developed by George Church, a professor of genetics at Harvard Medical School and co-founder of Colossal.
Something like a thylacine, but what comes next?
The announcement of the genetic breakthrough came ahead of an event at the SXSW festival in Sydney on Friday, where Lam and Pask will talk about their work with actor Luke Hemsworth. The Hemsworths have been vocal and financial supporters of the project.
The Colossal team is achieving many other milestones in its recent work, including developing the first artificial reproductive technology to stimulate ovulation in marsupials, a move that could lead to captive breeding programs for endangered species.
They say they have fertilized single-cell embryos, grown them more than halfway through pregnancy in an artificial womb, and improved ergonomic resistance to cane toad toxins in the cells of another marsupial, the northern marsupial.
As for when thylacines might form, Pask says he expects the first “thing that looks like a thylacine” to be born within three to five years, but he “wouldn’t call that a thylacine.”
He says researchers are confident they have created a skull, legs and even stripes for the Tessenian tiger, but “there are still other things we don’t yet know how to do.”
Other scholars are watching the matter with varying degrees of caution and skepticism. Some wonder why so much funding and effort is being put into bringing back species when thousands that still survive are on the brink of extinction. Euan Ritchie, professor of wildlife ecology and conservation at Deakin University, says it is an ambitious project and is likely to lead to breakthroughs that could help conservation. But he says there will be other challenges “if and when we bring back the Tasmanian tiger-like animals.”
“I think we’ll probably get some thylacine-like animals, but they won’t actually be thylacines. The question is: what’s next?” He says.
“How would they behave in the wild and what impacts might they have on ecosystems? We have no idea how they would behave because there are no thylacines left, and when you can bring back a thylacine, they won’t have any other thylacines to learn.” From her.
“This is at least as big a challenge, if not bigger, than the genetic challenge. As an ecologist, this is the big unknown.”
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