For the first time scientists recover RNA from an extinct species

In a groundbreaking study, researchers have successfully isolated and sequenced RNA molecules from a Tasmanian tiger specimen that had been preserved at room temperature in a museum collection for over a century.

This achievement marks the first time that RNA has been recovered from an extinct species. The research resulted in the reconstruction of skin and skeletal muscle transcriptomes from the extinct animal, shedding light on gene expression and regulatory mechanisms.

The Tasmanian tiger, also known as the thylacine, was a remarkable apex carnivorous marsupial that once inhabited Australia and Tasmania. It faced extinction due to European colonization, with bounties placed on the animal as an agricultural pest. The last known living Tasmanian tiger died in captivity in 1936.

Efforts to potentially resurrect the Tasmanian tiger have intensified in recent years, as its natural habitat in Tasmania is still relatively preserved. However, such endeavors require comprehensive knowledge of the species’ genome (DNA) and, equally importantly, its transcriptome (RNA) to understand tissue-specific gene expression and regulatory dynamics.

The study, conducted by researchers at SciLifeLab in collaboration with the Centre for Palaeogenetics (a joint venture between the Swedish Museum of Natural History and Stockholm University), involved sequencing the transcriptome of skin and skeletal muscle tissues from a 130-year-old desiccated Tasmanian tiger specimen. This effort led to the identification of tissue-specific gene expression patterns resembling those found in contemporary marsupials and placental mammals.

Remarkably, the researchers obtained transcriptomes of exceptional quality, enabling the identification of muscle- and skin-specific protein coding RNAs, as well as the annotation of missing ribosomal RNA and microRNA genes. This discovery also revealed the existence of thylacine-specific regulatory genes, such as microRNAs, that had become extinct over a century ago.

The study opens new avenues for future research by demonstrating the potential to recover RNA from other extinct animals and even RNA virus genomes from specimens stored in museum collections. This pioneering work promises to advance the field of palaeogenetics beyond DNA, offering exciting opportunities for exploring historical RNA data and its implications for understanding evolution and biology.