“In this photo I’m checking my team’s store of stem cells of the fat-tailed dunnart (Sminthopsis crassicaudata), a mouse-like marsupial that is the closest living relative of the thylacine, or Tasmanian tiger (Thylacinus cynocephalus). This mammal was an Australian apex predator, the size of a big dog. It once thrived throughout the continent but went extinct — first on the Australian mainland, and later in Tasmania, where it was hunted for hides and to reduce sheep attacks.
The last thylacine, ‘Benjamin’, died in captivity in 1936, on 7 September — a date that is now marked as World Extinction Day.
Here at the TIGRR laboratory, our main project is to bring back the thylacine by using gene-editing technology with cells from animals such as the fat-tailed dunnart. To achieve this, we’re trying to produce a complete genome for the species. We sequence DNA from historic specimens, using cells from young thylacines that had been kept for more than 100 years in alcohol preservatives. We compare that DNA with the dunnart genome and work out the gene edits that we would have to make to the dunnart cells to engineer a thylacine.
We’re also developing cloning and in vitro fertilization (IVF) techniques for use in marsupials (such techniques are already well established for other mammals).
When we restore the genome and thus create a complete thylacine cell, we’ll be able to use cloning, alongside IVF, in dunnarts to create living animals. My motivation is not to create an animal that goes into a zoo. We want to put the thylacine back into the environment, where it can help to address imbalances in the ecosystem.
People say we are playing God with our work. But we played God when we wiped out the thylacine. My research is looking at ways to heal lost biodiversity.”
This interview has been edited for length and clarity.