In a groundbreaking scientific achievement, researchers have achieved what was once deemed impossible: extracting and decoding RNA from an extinct animal. This milestone in genetic research brings us closer to unraveling the secrets of the Tasmanian tiger, also known as the thylacine, and potentially paves the way for the revival of this iconic marsupial.
The thylacine, with its striking appearance featuring dark stripes across its tawny coat and a jaw capable of a jaw-dropping 80-degree gape, was a remarkable creature. However, its existence was tragically cut short by human activity. As sheep farming thrived in Tasmania during the 1800s, the thylacines found themselves implicated in livestock killings. A bounty system targeting these animals pushed them to the brink of extinction.
In recent years, geneticists have mapped the thylacine’s DNA, along with other extinct creatures like the woolly mammoth. Yet, these efforts focused solely on DNA, leaving a crucial gap in understanding how these creatures’ cells truly functioned.
The breakthrough came in 2020 when Emilio Mármol-Sánchez and his team stumbled upon a preserved thylacine specimen at the Natural History Museum in Stockholm. This unexpected discovery opened the door to a remarkable endeavor.
The researchers carefully collected six small samples of skin and muscle from the desiccated thylacine. In the laboratory, they processed these samples, isolating nucleotides—the RNA building blocks. A computer algorithm then compared these nucleotide sequences to an extensive database containing genomes from various species, including the thylacine.
The astonishing result? Approximately 70 percent of the RNA sequences retrieved were confirmed to be thylacine-specific. Some contamination from human RNA was expected due to handling the specimen.
This analysis unveiled distinct protein-coding RNA molecules in skin and muscle samples. Each served specific functions within the body. For instance, the research identified RNA molecules responsible for instructing cells to create slow-twitch muscle fibers, crucial for endurance.
In a revelation that sheds light on cellular policing, the team identified over 250 thylacine-specific short RNA molecules called microRNAs. These sequences play a vital role in regulating cell functions.
These findings are nothing short of remarkable, according to Andrew Pask, a developmental biologist at the University of Melbourne. RNA is far less stable than DNA, making its extraction from a specimen stored at room temperature a remarkable feat. Pask believes this discovery will revolutionize how museum and archive specimens are viewed in scientific research.
Looking ahead, researchers are exploring the possibility of bringing the thylacine back to its native Tasmania through de-extinction efforts. By modifying the genes of the fat-tailed dunnart, one of the thylacine’s closest living relatives, these new RNA insights could provide critical information about the genes controlling the thylacine’s unique attributes. It’s a promising journey into the past with implications for the future of conservation and genetic science.