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Move aside Jurassic Park, meet the man who is running the ‘de-extinction’ of the Tassie Tiger

A philanthropic donation of $5 million to the University of Melbourne will fund a world class research lab which could result in the “de-extinction” of the Tasmanian tiger.

The money will be used to establish the Thylacine Integrated Genetic Restoration Research (TIGRR) lab to develop new technologies. These include completing the sequencing of DNA structure and genetically engineering DNA code, in an attempt to bring the Tasmanian tiger back from extinction.

Thylacine is the scientific name for a Tasmanian Tiger.

I caught up with Professor Andrew Pask, who is leading the research team, to see what the process of ‘de-extincting’ an animal involves, outside from what we’ve seen in Jurassic Park.

[IMG DESCRIPTION] A toy Tasmanian Tiger, light brown with brown stripes, sits surrounded in green bushland.

Q: How did a passion for the Tassie Tiger grow into the tangible basis for this project?

A: I was always really interested in genetics, that was my major at university. I really loved it, and then I got the opportunity in my honours to work on marsupial genetics which was the combination of my passion for wildlife and marsupials, but also the genetics work that I was doing. Then very early in my career, I started isolating genes for marsupials and seeing if I could get them to work in a mouse, we had this idea that it would be amazing if we could amplify a gene from the extinct Thylacine [Tassie Tiger] and bring that gene back to life.

So, this is just one tiny, tiny piece of the genome [all genetic information], but nobody had done that before. Nobody had accessed the DNA from an extinct animal and seen if we could resurrect the function of the element. So, we did that, and we actually published the first paper ever on bringing extinct DNA back to life, [doing so] with DNA in a mouse with a little bit of Tasmanian Tiger DNA.

From then on I was really hooked on the idea of; could we do this for the entire genome – and could we start to think really seriously about using genetic engineering technology to bring this animal back?

[IMG DESCRIPTION] A tray of test tubes in a scientific lab, with a pipette adding liquid to one of the tubes.
Photo by Louis Reed on Unsplash

Q: Are there challenges when mapping a DNA genome?

A: One of the biggest problems is for animals that have gone extinct, the DNA is very old and the older it is, the more broken up it is. It is in lots of tiny, tiny little pieces.

I always say it’s like doing a puzzle. You’ve got your entire genome broken up into tiny little puzzle pieces, but the problem with our genome – our own as a human, but also every mammal, including the Tassie Tiger, is that half of our genome is made up of repeat sequences. Creative code over, and over, and over again, so it’s like doing one of those puzzles that’s all jellybeans or spaghetti.

One of those horrible nightmares is where you’ve got to try and figure out how all those pieces go back together – and of course, for an extinct animal, we’ve got no picture on the box or guidance on what it should look like.

[IMG DESCRIPTION] A collection of blue puzzle pieces on a grey table, they are scattered and unorganised.

Q: What changed? It sounds like it’s gone from an impossible project to something more tangible.

A: Well, it was, but then with massive advances in the way we can sequence DNA we can put the puzzle together again. So we use things like machine learning, artificial intelligence, and supercomputers to rebuild this puzzle for us, and so all of a sudden it becomes something that’s a very real possibility. So once we could do that, I was like, we have got to do this for the Tasmanian Tiger.

It was a lot better than I thought it would be. It [the DNA code] was a lot more complete than I thought we would get. When we did that [rebuild], we got a phenomenally good genome. We’ve been able to nearly map the entire DNA code back together. And so, then it opened up the idea that we could seriously bring this back.

[IMG DESCRIPTION] A strand of DNA made up of white, blue, and black particles, as if it is being sequenced or built
Photo by Sangharsh Lohakare on Unsplash

Q: There have been concerns about the ethics of this project and whether you are “playing God.” How do you respond to these concerns?

A: I think comments like “playing God” are really easy [to address], because we were obviously playing God when we wiped Tassie Tigers off the face of the earth, and nobody stopped to think if it was right or wrong until it was too late. So, I think we’ve already “played God” and if we have the technology to bring these animals back, then we owe it to the species that we have completely exterminated to do everything we can to restore them.

Obviously in the case of the Tassie Tiger it has enormous benefits for the ecosystem as well, and they’re really important for the whole ecosystem in Tasmania. So there’s a lot of really good reasons for wanting to do it.

With the ethics of ‘is this where we should be spending money?’ We were given a philanthropic donation. So, this could be from somebody who could have spent money on a new house or something else, but instead they’ve decided to put it into conservation research and thylacine restoration. This money hasn’t been taken away from other conservation efforts, and I really firmly believe that the technology we’re developing is so important for the conservation of existing marsupials. That’s the real benefit of the research, it’s not just about bringing the Tassie Tiger back, it’s about developing a heap of really important tools we can apply to marsupials before we lose even more of them.

Q: What is the difference between cloning and mapping a genome?

A: With cloning you have to start with a living cell. We can do cloning with any placental mammal, particularly mice and rats which we do in labs all the time. In marsupials we don’t yet have that technology, so we have to figure that out. But it still requires a living cell, which we don’t have for an extinct animal.

For this [project], you start off with the cell from whatever the closest living relative to the species that went extinct is. And then genetically engineer that cell to become a Tassie Tiger by changing all the bits of its DNA code where it’s different from that living animal into what the Thylacine [Tassie Tiger] genome looks like.

Q: And you are using cells from the Dunnart Mouse to map the Tasmanian Tiger’s genome?

A: Yeah, so far it looks like the Dunnart is the closest living relative. That’s really handy as well because they’re not an endangered marsupial, they’re completely non-threatened, and they also breed really well in captivity, so they’re really easy for us to work with.

[IMG DESCRIPTION] A Dunnart mouse on a grey stone, the background dark and blurry.
A Dunnart Mouse, image sourced from Wikimedia Commons

Q: So, you’ve got the completed genome, you’ve got the Dunnart, what are the steps now?

A: That DNA editing part, turning the Dunnart cell into a Thylacines is huge. Although it’s only a small percentage of the genome that’s different between them, we’re still talking millions of bits of code that need to be edited, so that’s still a very time-consuming process. You have to be really careful, double, triple, and quadruple check every single part because you cannot make a mistake. Otherwise, you’ll have a different animal that isn’t a Thylacine, and that’s not what we want.

[IMG DESCRIPTION] A healthy Tasmanian Tiger, its mouth open and eyes closed, caught mid yawn and showing it's sharp teeth.
The Tasmanian Devil – the modern apex marsupial, photo by Meg Jerrard on Unsplash

Q: You mentioned earlier that this work will go on to protect modern marsupial species. How?

A: Yeah so they reintroduced wolves in Yellowstone National Park – that’s a really good case study. They were hunted out of existence in Yellowstone and were then reintroduced. And they’ve shown that the benefits of that, the entire ecosystem, have just been so surprising. Tiny species they didn’t think would be impacted by the wolves are coming back and flourishing as a result of putting the wolves back in that environment.

Now we know for the Tassie Tiger that they were the only apex predator [in Tasmania] that we had, the only one of those animals that sits right at the top of the food chain. So when you remove those from an ecosystem, you do start to see all sorts of weird things happening with those [remaining] species.

A great example of that is the really strange Tasmanian Devil facial tumour disease that emerged. All of a sudden, the Tassie Devil got this transmissible cancer that nearly rendered them extinct. So when you’ve got an apex predator, they will pick off the weaker and sick animals – and would stop those animals from spreading that disease – that’s the kind of role they play in the ecosystem. So it’s possible if we never lost the Tassie Tiger, we could have prevented the spread of that disease.

Q: Since the Tasmanian Tiger was made extinct, what has occurred in the ecosystem?

A: Tasmania is pretty much unchanged since they were made extinct in the 30s. A lot of people focus on how the Tassie Tiger has been extinct for 90 to 100 years, but the thing about ecosystems is that they take thousands, tens of thousands, sometimes hundreds of thousands of years to change. So when you lose an animal at the top, the ecosystem cant quickly adjust to compensate for the loss of that species. It takes forever for that ecosystem to adjust. So in Tasmania it’s exactly as it was when the Tassie Tiger was around, so the ability to put that animal back into its native environment is there.

One of the great things about this particular animal is that we’re not recreating something that hasn’t been around for tens of thousands of years, we’re creating something where we can literally put straight back into the environment where it came from. It’s why it’s different from reintroducing, say, a mammoth.

[IMG DESCRIPTION] A toy Tasmanian Tiger, light brown with brown stripes, sits in a bunch of dried wattles in front of a scene of dinosaurs.

Q: And finally, are we putting the Jurassic Park comparisons to rest?

A: Credit where credits due, the technology they say they’re going to use to bring back the dinosaur is not that far off to what we actually do. We can sequence the DNA and then fill the gaps – what they use is a frog, which you would never use by the way, there’s a massive oversight there. But, that’s basically the same principle we’re doing here. The big thing is, you don’t want to bring back animals that have been dead for several million years that never coexisted with humans, that’s never going to be a good thing to do, regardless of the story telling.

In this instance, bringing back a recently extinct animal back into its same environment has good cause for doing it. Jurassic Park definitely put the concept on the map, but I think like all film depictions of scientists, the scientists are always the villains, it’d be nice to turn that around and show there’s an awful lot of good that comes out of science.

Original photos by Celeste Gibbs