🧬 Geneticists Deciphered the Tasmanian Tiger’s RNA Mysteries

In a groundbreaking study, scientists have successfully sequenced RNA from the extinct Tasmanian tiger, overcoming the notorious instability of RNA, which typically degrades rapidly outside living cells.

The Tasmanian tiger, also known as the thylacine, was a carnivorous marsupial indigenous to Tasmania in southeast Australia. The last known animal died in captivity in 1936. Although the distinctive, dog-like creature vanished, several specimens remain preserved in museums, serving as time capsules of a bygone species.

Venturing into the heart of this extinct creature’s genetic code, scientists extracted thylacine RNA from a 132-year-old specimen at the Stockholm Natural History Museum. The analysis extended beyond merely charting the genome; it elucidated the function of critical genes. For instance, muscle samples showcased genes for actin and titin, proteins integral to muscle movement and elasticity, while skin samples revealed the genes responsible for keratin, ensuring skin toughness. Intriguingly, the RNA also bore traces of ancient viruses that lived in or infected the Tasmanian tiger.

Such discoveries fuel the idea that museum-preserved specimens could unlock insights about extinct species and potentially even guide efforts to bring some back to life.

Companies like Colossal Biosciences are harnessing state-of-the-art gene editing tools and recent cloning advancements to recreate species such as the Tasmanian tiger. Their ultimate goal? Reintroduce these animals to their ancestral habitats.

Bringing back the Tasmanian tiger is like assembling an IKEA table. Even if you have all the parts, there’s always that one crucial piece missing: the instructions. 

Yet, the roadmap for the thylacine’s revival is clear: first, decipher its genome. Next, identify a compatible genomic donor. The fat-tailed dunnart, a swift-breeding mouse-like close relative of the thylacine, has been chosen for this role. Already genomically mapped, this diminutive creature will serve as a genetic scaffold. Scientists aim to transform dunnart cells into “marsupial wolf” cells using CRISPR/Cas9. These modified cells would craft an embryo, eventually nurtured by a fat-tailed dunnart surrogate.

The researchers’ optimism is bolstered by the thylacine’s short gestation and minute offspring size, which means that even a miniature marsupial could feed them.

It is worth noting that it is not a Jurassic Park situation. The driving motive isn’t spectacle but ecological repair. Tasmania’s ecosystem imbalance after the thylacine extinction might find some remedy if these hybrids can regulate local herbivore populations of kangaroos and wallabies.

But, resurrecting extinct species carries complex scientific, ethical, and ecological baggage. While a recreated animal might genetically mirror its ancestors, its behaviour may differ. Moreover, the ever-present risk of these species disrupting current ecosystems or failing to thrive exists.

A 2017 study highlighted a poignant reality: funds devoted to conserving endangered species yield greater biodiversity returns than similar investments in de-extinction efforts. As Joseph Bennett of Carleton University aptly said, “It is better to spend money on the living than on the dead.”

Elia Kabanov is a science writer covering the past, present and future of technology (@metkere)

Illustration: Elia Kabanov feat. MidJourney.