The 110-Year-Old Pickled Fossil Skull Of A Tasmanian Tiger May Help Bring The Extinct Species From Australia Back To Life

PIXATERRA
PIXATERRA - stock.adobe.com - illustrative purposes only, not the actual Tasmanian tiger

Scientists have used a century-old pickled fossil skull to reconstruct the most complete Tasmanian tiger genome yet. It could help bring the extinct species back to life.

The effort was led by the company Colossal Biosciences. It was made possible due to a 110-year-old head that was preserved in ethanol.

The well-preserved specimen allowed the researchers to assemble most of its DNA sequence, along with strands of RNA that show which genes were active in the animal’s tissues at the time of its death.

Many experts believed it was impossible to reconstruct a full genome from ancient samples, but this new project proved them wrong.

The Tasmanian tiger, also known as the thylacine (Thylacinus cynocephalus), was a carnivorous marsupial that played a vital role in the Tasmanian ecosystem. By 1936, it became extinct after decades of being hunted by humans.

Since the species went extinct fairly recently, there are still many well-preserved specimens stored in museum collections, and research centers all over the world that can be used for their de-extinction process.

The newly constructed genome is similar in size to a human genome. It is made up of three billion base pairs of nucleotides, which are the molecules that serve as the fundamental building blocks of DNA.

The DNA sequence still has 45 gaps. The scientists hope to be able to fill them in with further sequencing in the months to come.

The RNA fragments discovered in the pickled head helped the researchers determine the genes that were active in different tissues when the thylacine was alive. They then can figure out how the creature’s brain functioned and what it could see, smell, and taste.

PIXATERRA – stock.adobe.com – illustrative purposes only, not the actual Tasmanian tiger

RNA is more unstable and prone to damage than DNA, so it is usually less likely to be preserved. In this case, its preservation has provided the researchers with more information about the thylacine’s biology than ever before.

Another breakthrough in the thylacine de-extinction project has implications for the conservation of a living species. It involves using assisted reproductive technologies (ART) to trigger ovulation in a small, mousy marsupial called the fat-tailed dunnart (Sminthopsis crassicaudata).

It is the closest living relative of the Tasmanian tiger. Once the fat-tailed dunnarts produce a bunch of eggs, the researchers will inject the finalized thylacine genome into them. The research team also plans to use fat-tailed dunnarts as surrogates to grow thylacine embryos.

In addition, the team is working on perfecting the creation of an artificial device that can grow marsupial embryos. The device is now able to carry embryos from the beginning to midway through pregnancy.

“They are all huge breakthroughs,” said Andrew Pask, a professor of genetics and developmental biology at the University of Melbourne in Australia, who helped put together the Tasmanian tiger genome.

“The development of ART for marsupials has major implications for captive breeding for endangered marsupials—but is also paving the way for us to create a living thylacine once we have the edited cells.”

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Emily  Chan is a writer who covers lifestyle and news content. She graduated from Michigan State University with a ... More about Emily Chan

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