Scientists from University of Melbourne have announced the start of an ambitious scientific project. They intend to revive the Tasmanian marsupial wolf (thylacine), which became extinct in the 1930s. According to researchers, the extinct animal can be recreated using stem cells and gene editing technology, and will return to nature in 10 years.
We tell how scientists want to do it, and there are there similar projects in Russia.
One day you will see it again in thickets»
Initially, thylacine was found in mainland Australia and on the island of New Guinea, but disappeared from there for about 3 thousand years and remained only on the island of Tasmania, which is 240 kilometers from Australia. European settlers considered it dangerous for sheep and deliberately exterminated it: a premium was given for the head of each animal killed. The last marsupial wolf in the wild disappeared in 1930 the year and the last captive thylacine died in the zoo.
In 1999, the Australians announced a program to clone the Tasmanian wolf. At the disposal of scientists there are alcoholized puppies of this animal. DNA fragments were extracted from them, however, they turned out to be damaged and unusable. The fact is that cloning requires a complete genome, and it is impossible to find a whole DNA molecule without breaks in dead tissues. More precisely, it is theoretically possible (miracles happen), but scientists have not been able to do it yet.
Nevertheless, in 2008, the second project for the revival of thylacine was launched. Researchers at the University of Melbourne have inserted DNA fragments from a marsupial wolf into a mouse embryo. This helped them to observe how genes work. And now, a partnership with the American biotechnology company Colossal Biosciences has been announced. She is ready to provide a grant of 10 million dollars, which will allow an international team of 50 scientists to work on the thylacine revival project in comfortable conditions.
“We can take a giant step forward in solving such an enormous task as the resurrection of extinct animals. I am sure that in 10 years we may have the first live thylacine cub, — says Head of the Comprehensive Research Laboratory for Genetic Restoration of the Marsupial Wolf Andrew Pask. — Our ultimate goal — return this species to the wild, where it played an important role in the ecosystem. We hope that one day you will see it again in the Tasmanian bush.
Marsupial wolves at the New York Zoo, 1902 Source: Public Domain
How can a mouse bear a wolf?
Scientists want to restore thylacine DNA using the CRISPR method, which allows editing the genome. First, they will create the complete genome of an extinct marsupial wolf and compare it with the genome of its closest living “relative” — fat-tailed marsupial mouse. Then they will take germ and stem cells of this mouse species and change in them those areas of DNA that differ from such the same areas of thylacine DNA. Thus, a molecule with the complete genetic information of an animal that disappeared almost a century ago will be recreated in the laboratory.
Next — cloning procedure. Scientists will select a female fat-tailed marsupial mouse, replace the nucleus of her egg with thylacine DNA, and create an embryo that this female will bear as a surrogate mother. Of course, here the question arises: how can a mouse bear a cub of a wolf, because they have a big difference in sizes? — but biologists have an answer for it. All marsupials are born very tiny, they say, so this won't be a problem.
Helping Australians resurrect the Tasmanian marsupial wolf, Colossal Biosciences is known for its DNA editing work and attempts to clone the mammoth. One of its founders — famous geneticist, Harvard professor George Church — more than once promised to return the furry giants, destroyed by man, into the wild. He and suggested a technology with which this can be done. Under Church's leadership, some work has already been done: scientists have inserted into the genome of elephant skin cells those mammoth genes that are supposedly responsible for the typical characteristics of this animal — small ears, a thick layer of subcutaneous fat, long hair and brown color. And the cells were able to survive this transformation. As Colossal Biosciences now assures, in 6 years they will be able to create the first mammoths using an elephant embryo and replacing certain genes in it.
A can can can ;Save it?
American researchers are working with mammoth tissue samples found in 2018 in Yakutia. And if they manage to revive this animal, it will most likely live in Yakutia too.
Since the late 1980s, a unique scientific project — “Pleistocene Park”. Its purpose — to restore the so-called mammoth tundra-steppe, which once fed herds of herbivores of many millions. This ecosystem existed during the last glaciation and was ten times more productive than the forest-tundra that appeared in its place. More than 10,000 years ago, woolly rhinos, bison, musk oxen, horses, deer, and, of course, mammoths lived there. They all ate grass and fertilized the soil with organic matter in the form of manure.
Now scientists have repopulated these lands with some species of animals — Yakut horses, reindeer, elks, bison, musk oxen and yaks. And, of course, they dream of a mammoth returning there. It is the “Pleistocene Park” should receive the first mammoths bred in the laboratories of Colossal Biosciences, if it can be done.
“Technically, we”ll be ready to accept a mammoth in five to seven years, — reasoned a year ago the director of “Pleistocene Park” Nikita Zimov. — But even if the first mammoth is born at this time, I categorically want to let a newborn baby into Arctic region. It is necessary to first form a small population, at least a few individuals, and so that they reach at least adolescence.
One of critical objections to the very idea of the return of the mammoth to nature is precisely that is that one or two individuals in will have nothing to do. “For the park, it is necessary to create a heterogeneous population, here the matter will not be limited to one cute mammoth or cave bear cub. You need to have several hundred individuals that are genetically different from each other. Otherwise, inbreeding, inbreeding, and inevitable degeneration will occur, — notes Doctor of Biology Konstantin Severinov.
But what to say about hundreds of mammoths, if recreating one is a difficult scientific task? In order to solve it, several unlikely factors must coincide. Even if you manage to find intact DNA or construct it by bioengineering methods, you will have to somehow extract an egg from a living elephant, and then, having performed all the necessary manipulations with it and fertilizing it, put it back. And then, holding fists, hope that the embryo will not be rejected (after all, this is a different biological species!) And the surrogate mother-elephant will be able to bear the fetus. Finally, it is necessary that the mammoth was born without defects and did not die in the first weeks, which also cannot be guaranteed.
But it makes sense to ask one more question. Every year, due to the fault of man and his extensive activities, hundreds of species of animals and plants disappear from the face of the planet, and the areas and populations of those that still exist on it are rapidly declining. Why don we try to first try to save those who still live near us? And then after all, you look, and we won't be able to save the reborn mammoth.
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