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How to bring a frog back from the dead … well, nearly
News Grab (2): It sounds like part of the plot from Jurassic Park, but Australian scientists have taken the first step in bringing an extinct species back to life.
Belinda Smith: It's a tantalizing thought, isn't it? To hit control Z and undo something thought permanent to bring an animal back from the dead. Nearly two decades ago, a small group of scientists came surprisingly close to resurrecting the extinct gastric brooding frog. These creatures lived in creeks in Queensland, rainforests, and while they looked like your bog standard frog, you know, [00:13:00] bulgy eyes, mottled skin, they did something extraordinary. They reared their young in their stomach, the only frogs we know of that could do this. But by the mid-eighties, they'd all hopped off this mortal coil, largely thanks to a deadly fungus.
ABC Science reports Jacinta Bowler has this story about the painstaking efforts to bring the frogs back.
Jacinta Bowler: It's March, 2008, and frog expert Michael Mahony can barely believe his own eyes. He's peering through a microscope at cells, a few dozen tiny brown blobs on a glass dish, and they seem to be dividing.
Michael Mahony: Two or three out of the 50 would start to divide and you're going, whoa. It's actually happening. First division, then they go into second division and, and we're, you know, at that moment you really are high fiving.
Jacinta Bowler: Look, in normal circumstances, cell division doesn't cause high fives. But these are no ordinary cells.
They're from the long extinct gastric brooding frog. And Michael's team was trying something thought impossible de-extinction. Appropriately. The team was called Project Lazarus, a nod to the Bible story where Jesus brought a dead man back to life. But in that story, the resurrected Lazarus had been dead for just four frog the team was trying to bring back had been stuffed in a freezer for a few decades, and on that day, in 2008, they'd done it.
Michael Mahony: What else can this be, but the gastric brooding frog? Brought back,
Jacinta Bowler: but this early success would be very short-lived. Michael Marney's work with the gastric brooding frog started long before he joined Project Lazarus. He'd spent a decent chunk of the eighties trudging through the rainforest of Queensland, searching for the frogs which lived on the ground and were about palm sized. But what really captivated Michael was the fact that the gastric brooding frog was the only species we know of that looked after their young in their stomach. So the female would lay eggs. Eat them. And once they turn from tadpoles into small frogs, she would vomit them back up again and her babies would hop off and start their new lives.
Michael Mahony: Uh, so there are two, uh, species of gastric brewing frog and the first one was discovered in 1973, not far from Brisbane, about uh, 150 kilometers north of Brisbane, uh, by a guy named David Liam.
Jacinta Bowler: That one was called the southern gastric brooding frog.
Michael Mahony: And by 1980, uh, that frog had disappeared in the wild. And then in 1984, while doing field work in the rainforest of Queensland, a group of people I was with, um, we discovered a second species of gastric brooding frog, about 80 kilometres west of Mackay.
Jacinta Bowler: That's the northern gastric brooding frog.
Michael Mahony: So it was discovered in 1984, and then, um, by the end of 1986, it unfortunately it also disappeared in the wild.
Jacinta Bowler: Unfortunately these two frog species were not the only ones that Michael has seen dwindle
Michael Mahony: and disappear. We'd been further north to the rainforest of the wet tropics looking at, um, some specialist frogs that live only in the wet tropics rainforest.
And we started to have a, a sense that things weren't right 'cause we couldn't find things in lots of places where they used to be. And so after the disappearance of the second gastric brooding frog, a lot of scientists in Australia, frogs, biologists at least, were, were having discussions about, well, things are disappearing and what's going on?
Jacinta Bowler: It turns out that a deadly fungus called kitr was to blame. It kills by thickening the frog [00:17:00] skin, which disrupts the ability to balance salt and water levels and can even stop them breathing.
Michael Mahony: Since then, the, the late 1980s, it's been a sort of a constant battle to, to map this disease and try and understand which, uh, which frogs will be next to, um, to go.
So in the last decade, um, the lab I work in and with colleagues, I think we described something like six new species of Australian frogs. And, and four of them, the moment they were described, were listed as endangered under the, um, the national Threatened species list. And they're listed as endangered 'cause they're down to the last four or five populations.
And so. They're already on the vortex to extinction. Um, this is one long continuum for the conservation biologists. It's saving habitat, saving species, saving populations, sometimes being involved in triage, you know, collecting the last individuals of a population to go into a captive husbandry so that it, we still have it, we've still got some chance of it not going completely,
Jacinta Bowler: and when it does go completely. What if it's the final last ditch attempt when all others fail? Michael turned to de-extinction.
Michael Mahony: And of course it's far better that animals and plants are protected and don't get to that, the problem of going extinct. But what we now know is that for most animals that are going extinct, it's been human cause. It's our responsibility. And it doesn't seem to me a, a fast step to say. You know, the animal's only gone 20 or 30 years and we have some genetic material. Should we try and recover it? He wasn't the only one thinking about these things.
Jacinta Bowler: Project Lazarus was the brainchild of Professor Mike Archer at the University of New South Wales, who brought together a number of researchers with a specific set of skills to try and [00:19:00] resurrect the gastric brooding frog. Michael was there
Michael Mahony: because I, inverted commas, knew a bit about Australian frogs.
Jacinta Bowler: Andrew French was one of two cloning experts brought on.
Andrew French: I met, um, professor Michael Archer through a colleague of mine, professor Alan Tren. I was working for Alan and we were, we were looking to explore reproductive technologies across domestic and laboratory species, and I.
We just happened to sit down at a meeting one day when Professor or Michael Archer came along and we just discussed about applying these technologies to an Australian frog.
Jacinta Bowler: Another frog expert, one named Mike Tyler, just happened to have the gastric brooding frog in the back of his regular freezer. And yes, there are a lot of Mike's and Michaels in this story. Andrew French and his team,
Andrew French: we thawed the tissue. We looked at the cells. The cells seem to be all intact. All we're really after is the DNA in it because the machinery to manage and manipulate and grow that DNA is all found in the egg.
Jacinta Bowler: They had the DNA and were almost ready to go. After finding an appropriate surrogate frog species, which was the giant barred frog, and making sure the frozen cells were thawed correctly in 2008, they began work on resurrecting the extinct gastric brooding frog.
At Easter, during the giant barred frog's breeding season, they'd carefully take eggs from the surrogate frog, remove the DNA inside and replace it with decades frozen DNA.
Andrew French: We, we were just excited, but we always wanted to have, uh, repeatability and we always wanted to make sure that, you know, what we were doing was actually, you know, reactivating the genome of this extinct frog.
Jacinta Bowler: Almost immediately they had success. A few of the cloned frog eggs began to divide much to Michael Marney's delight as he watched them growing under the microscope, but it didn't.
Michael Mahony: Last problem was, is that within the next 24 hours, and we repeated that experiment numerous times, uh, the embryos would start to die.
About 24 or 36 hours later,
Jacinta Bowler: Michael and his colleagues could not figure out. What was happening?
Michael Mahony: Yeah, I mean it, it's be Deviled us.
Jacinta Bowler: Project Lazarus tried the process every Easter and in 2013 they went public with what they'd been able to do so far
News Grab (3): using cloning technology. They've reactivated the DNA of a frog that was wiped out more than 30 years ago. Extinct Frog has landed Newcastle Scientists in Time magazine's 25 best inventions of 2013.
Jacinta Bowler: While news reports at the time suggested that this de-extinction effort was the first of its kind, that's not quite true. Let's leave the Newcastle Frog Lab for a moment and head to the Pyrenees Mountains In the year 2000, a mountain goat found in Spain called the Pyre, and Ibex died out on a tree from the last surviving member of the species, A female called Celia.
Using the same technique, project Lazarus used scientists in Spain, created clone embryos of Celia and implanted nearly 200 of them into 57 surrogate goats. Seven of those surrogates became pregnant, and just one gave birth In July, 2003, Celia Species was the first to become de extinct, but only for about 10 minutes.
The baby quickly died. The Pyran and Ibex is now known as the only animal to have gone extinct twice. If Project Lazarus had succeeded, the gastric brooding frog might have shared the same fate as the mountain goat. Kitt fungus, which killed both species of gastric brooding frog. The first time round is still wiping out species in Australia and around the world.
Critics of de-extinction argued that releasing the gastric brooding frog back into the wild would simply leave it vulnerable to Kitt infection and dying out all over again. Plus, if cloned frogs were able to be bred and keep in mind, currently there was only one frog. One sex, any offspring would be severely
Michael Mahony: inbred to see all of those they're all true, but the first thing is to have an idea and to, to put it out there. And so I like to think, um, the thine and the mammoth, for example, are what I call flagships. You know, where somebody puts out a real challenge and that gets attention. And all of the other smaller things that are happening.
You know, the genetic work that's going on to prevent extinction, you don't hear about it in the media very often at all. People are beavering away day after day in labs all over the country working to prevent the loss of genetic diversity from our, from our native animals.
Jacinta Bowler: It's in this landscape. The next generation of de-extinction efforts have already begun trying to bring back animals like the thine and the mammoth.
In April, according to biotechnology company, colossal Biosciences,
News Grab: 13,000 years after the last dire wolf walk the earth. Scientists say they've now brought them back
Jacinta Bowler: with gene edited puppies sitting on the throne from Game of Thrones. I can't lie, it is extremely cute. But putting that aside, no matter how cute the puppies are, some scientists reckon that calling them dire wolves is misleading.
They aren't clones of actual di wolves, but a gray wolves with a few genes change to make them more like di wolves. Still, Michael Marney is extremely chuffed about this.
Michael Mahony: I mean, there's been a lot of debate about whether it's a dire wolf or not. I mean, to me that is like, oh, guys, get over it. These technicians, these biologists have taken the total DNA of, um, the dire wolf from ancient DNA.
They've sequenced it. They've said these, these 14 genes, we can see gene sequence differences. They constructed that DNA, then they used a modern technique, um, of, um, called CRISPR, where they cut and placed that DNA into the embryo. And they, and they, um, were successful in transferring them to, um, surrogate mothers and then producing pups.
So this is just amazing. Like, uh, offspring with, um, you know, 14 new, um, genes put into it. They've shown that, um, the modern promise of of DNA technology can be used to recover, lost, um, genetic diversity. That, that's just incredible.
Jacinta Bowler: Whether the puppies are dire wolves or graywolf hybrids, colossal biosciences faces the classic problem of what happens next, and there's no plans at this stage to release the wolves into the wild.
Michael Mahony: I don't think we should discourage people developing the technologies and going there because if colossal had not done those things, I think. Well, who would've paid attention?
Jacinta Bowler: As for Project Lazarus, the team kept trying for a few more years, but eventually the whole project kind of petered out. Michael still has one researcher in his lab working on frog cloning, but it's mostly taken a backseat while Project Lazarus tried to bring the gastric brooding frog back to life.
Kitt continued to spread, affecting hundreds of species of frog around the world. According to the international union for conservation of nature, 36 frog species are now either extinct in the wild or extinct. Full stop. More than 660 are critically endangered. For Michael, anything that can stop the biodiversity crisis should be seriously considered.
Michael Mahony: We either go and save their habitat or we bring them into a, a zoo situation to breed them because they're going to go in the wild. And so some of Australia's, well, probably Australia's most iconic frog, the corrobor frog really only exists in, in, um. In zoos. Uh, a handful may be out in the wild left, but so de-extinction is preventing it from going extinct.
I mean, technically de-extinction is, yeah, it's gone. Now. We've gotta do some fancy genetic work to try and bring it back, but there's a lot of fancy work going on just to keep many, many species from dipping off the end.
Belinda Smith: That was Michael Mahony, emeritus Professor at the University of Newcastle, speaking to ABC Science reporter, Jacinta Bowler, and you are listening to the Science Show on a BC Radio National.
