In all For the species in which humanity has wiped out the earth, thylacine may be the most tragic loss. A wolf-sized marsupial sometimes called the Tasmanian tiger, the thylacine ended in part because the government paid its citizens bonuses for each animal killed. That end came recently enough that we have photos and videos of the last thylacines ending their days in the zoo. Late enough that in just a few decades, countries will begin to write laws to prevent other species from suffering the same fate.
Yesterday, a company called Colossal, which says it wants to bring back the mammoths, announced a partnership with an Australian laboratory that it says will make thylacine extinct with the goal of bringing back the mammoths. it comes back to nature. Some features of marsupial biology make this a more realistic goal than bringing back the mammoth, although a lot of work remains to be done before we begin the debate about whether Is reintroducing the species a good idea?
To learn more about the company’s plans for thylacine, we spoke with Colossal founders Ben Lamm and Andrew Pask, who heads the lab he’s working with.
Branching out
To some extent, the Colossal was a way of organizing and funding the ideas of Lamm’s partner, George Church. Church has been talking about the mammoth extinction for a number of years, spurred in part by developments in gene editing. The company is structured as a startup, and Lamm says it is open to commercializing the technology it develops while pursuing its goals. He told Ars: “On our path to genocide, Colossal is developing new software, wet software and hardware innovation technology that could have a profound impact on both conservation and healthcare. People. But it’s basically developing products for which there is clearly no market: species that no longer exist.
General approach born to mammoths is simple, even if the details are extremely complex. There are so many mammoth tissue samples from which we can obtain at least part of the genome, which can then be compared with its closest relative, the elephant, to find the key differences between the two. with mammoth lineage. Thanks to gene-editing technology, key differences can be edited into the genomes of elephant stem cells, essentially “making fat” for elephant cells. Then a little bit of in vitro fertilization, and we’ll have a furry monster ready to go to the subarctic savannah.
Again, the details matter. At the beginning of the plan, we did not generate elephant stem cells, nor did we make gene editing even a fraction of the scale required. There are credible arguments that the peculiarities of the elephant’s reproductive system make the necessary “little IVF” practically impossible; If it occurs, it will involve a pregnancy of nearly two years before results can be evaluated. Elephants are also social, intelligent creatures, and there is a fair debate as to whether their use for this purpose is appropriate.
Given these challenges, it may not be a coincidence that Lamm said the Colossal is looking for a second species that is going extinct. And the search turned up a project with an almost identical approach: Thylacine Integrated Genome Recovery Research Laboratorybased at the University of Melbourne and led by Andrew Pask.
In the bag
As with the Colossal mammoth plans, TIGRR intends to collect thylacine genomes, identifying key differences between that genome and related lineages (mainly the quolls), and then edit those differences into marsupial stem cells, which will then be used for IVF. It also faces some significant hurdles: no one has ever made stem cells from a marsupial, nor has anyone cloned a marsupial – two things that have at least been done in mammals. placental breasts (although not pachyderms).
But Pask and Lamm have shown several ways that thylacine is a much more controllable system than the mammoth. First, the existence of animals until recent years meant there were a lot of specimens in museums, and so, says Pask, we are likely to collect enough genomes to get a sense of what population genetic diversity — potentially crucial if we want to re-establish stable breeding populations.
