Almost 100 years after its extinction, scientists at The University of Melbourne are ready to try and bring the Tasmanian tiger (thylacine) back to life. The species has been declared extinct since the 1930s.
The initiative now has a partnership with the ‘De-extinction’ company, part of the US-based ‘Colossal Biosciences’ genetic engineering firm, which will provide the study team access to more DNA editing technologies as well as assistance from a group of top scientists from around the world.
The Thylacine Integrated Genetic Restoration Research (TIGRR) Lab, directed by Professor Andrew Pask, will greatly benefit from this collaboration.
Pask says that “a lot of the challenges with our efforts can be overcome by an army of scientists working on the same problems simultaneously, conducting and collaborating on the many experiments to accelerate discoveries.”
“With this partnership,” he added, “we will now have the army we need to make this happen.”
How Long Until We See a Living Tasmanian Tiger ?
According to Professor Pask, as this collaboration progresses, Colossal Biosciences will use its CRISPR gene editing and computational biology capabilities to reproduce thylacine DNA while TIGGR concentrates its efforts on developing reproductive technologies specifically suited to Australian marsupials, such as IVF and gestation without a surrogate.
However, according to Professor Pask, the main question is how long it might take until a living thylacine is seen. Pask believes that it will be possible to attain an edited cell within ten years. This would then allow for the de-extinction of the animal.
“With this partnership, I now believe that in ten years’ time we could have our first living baby thylacine since they were hunted to extinction close to a century ago,” he said.
Tasmanian Tiger Hunted by European Settlers
About three thousand years ago, thylacines were quite common throughout Australia but it was specifically Tasmania that the species thrived.
Tasmanian Tigers were being hunted to extinction by European settlers who considered it a danger to the Tasmanian sheep business. The last known captive thylacine passed away in 1936.
Among living marsupials at the time, the Tasmanian Tiger was unique. It had a huge head and a long, stiff tail, granting it its recognizable wolf or dog appearance that led to the description “long dog with stripes.”
A biobank of species, created from marsupial stem cells could be immensely beneficial in preventing their extinction. However, the emergence of such a thing would surely necessitate further technological advancements. Animals are vulnerable to extinction in such instances as the recent Australia bushfires, so such a bank would prove quite valuable.
Additionally, research on embryo growth and development, as well as marsupial cloning, can support species management plans and breeding efforts for these animals.
In a recent piece Professor Andrew Pask wrote for Pursuit, a blog run by The University of Melbourne, he outlined the processes necessary in accomplishing this remarkable feat of nine steps that would lead to the de-extinction of Australia’s thylacine.
9 Steps To De-Extinction of Australia’s Thylacine
The essential first step in any de-extinction project and the likelihood of de-extinction of the animal is completely reliant on the quality and accuracy of that genome. To date, the thylacine represents the highest quality extinct genome for any species (including the woolly mammoth and the dodo). However, this resource requires further improvements.
Since the thylacine genome was published in 2017, advances in genome sequencing technology provide many new options to further enhance the quality and formation of the genome.
The second step is one that has already been completed by the team. The sequence for several species which represent the thylacine’s closest relatives, including the dunnart or marsupial mouse, are already available, and the species which possesses DNA with the closest match will provide the living cells and template genome that can then be edited to transform it into a thylacine genome.
Thirdly, a large bioinformatics (or computational) project that compares marsupial genomes to identify all the differences would potentially need to be edited into the host’s genome to create a ‘thylacine’ cell. This element is currently a major objective of the new TIGRR lab.
The fourth step is now in development with the TIGRR lab and the Australian Research Council. Stem cells for a model marsupial species have already been derived, and the fat-tailed dunnart will be used for the development of many of the techniques that will be needed for the thylacine de-extinction.
As part of the TIGRR lab, methods that are efficient in all marsupials will be established, and, with this tool, biobank diversity can effectively be built for ‘at-risk’ marsupial populations to protect against the loss of potentially threatened or endangered species.
The fifth to seventh steps require the development of assisted reproductive technologies (ART) for marsupials and are in development with the TIGRR lab. These techniques are necessary in the usage of living stem cells to create embryos which can then successfully be transferred into a host species’ uterus.
Finally, the eight to ninth steps are where de-extinction efforts for marsupials have a distinct advantage over other mammals. All marsupials give birth to tiny young which complete development in the pouch while suckling milk. As part of the de-extinction process, this can be substituted with bottle feeding from a very young age, suggesting that these animals might not require long and complicated gestation times.
These nine phases will most likely take a decade or longer, but the work done along the way will benefit marsupials significantly. Such advancements would bring back the iconic Australian mammal that has long been extinct.