In a groundbreaking study, scientists have decoded the RNA of the extinct Tasmanian tiger, or thylacine. This marsupial, resembling a wolf, became extinct when the last known individual died in a Tasmanian zoo in 1936. The recent findings, sourced from a museum specimen approximately 130 years old, were published in the August edition of Genome Research. This research offers fresh insights into the biology of the thylacine and could potentially aid in efforts to resurrect the species.
The thylacine, characterized by its unique dark stripes and a jaw that could open over 80 degrees, was a remarkable creature. However, as sheep farming expanded in Tasmania during the 1800s, thylacines were often blamed for livestock deaths. This led to bounties for their extermination, driving them to the brink of extinction.
While the genetic blueprint of the thylacine and other extinct species like the woolly mammoth has been mapped in recent years, these studies focused solely on DNA. Emilio Mármol-Sánchez, a geneticist at the Karolinska Institute in Stockholm, emphasizes that only RNA can provide insights into the actual functioning of an organism's cells.
In 2020, Mármol-Sánchez's team discovered a thylacine specimen at the Natural History Museum in Stockholm. They collected samples from the specimen and, after a series of laboratory processes, determined that approximately 70% of the RNA sequences they identified were genuinely from the thylacine.
The team's analysis identified distinct protein-coding RNA molecules in the skin and muscle samples. They also detected over 250 thylacine-specific microRNAs, which play a crucial role in regulating cell functions.
Andrew Pask, a developmental biologist from the University of Melbourne, finds these results remarkable, especially considering the instability of RNA compared to DNA. The fact that the specimen was stored at room temperature rather than in sterile or frozen conditions makes the findings even more significant. Pask believes this research could revolutionize how we view museum specimens.
There are ongoing efforts to reintroduce the thylacine to Tasmania by genetically modifying the genes of its closest living relative, the fat-tailed dunnart. Pask suggests that the recent discoveries could provide valuable information for this endeavor, offering insights into the genes that determined the thylacine's characteristics.