By Eve Kirman
The gene editing power of CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) has been in use as an effective bacterial immune technique since the beginning of life on earth. However, it wasn’t until 2012 that Jennifer Doudna and her team of scientists from the University of California, Berkeley harnessed the unique DNA modifying properties of the CRISPR-Cas9 system. Able to fundamentally ‘cut’ and ‘paste’ specific genes, CRISPR has unearthed limitless possibilities in the field of genetic manipulation.
Not only does CRISPR hold promise in curing diseases such as muscular dystrophy, cystic fibrosis, and even cancer, it also opens a world of creativity in terms of genetically modified organisms. Already, CRISPR has been used in breeding coffee plants that produce decaffeinated coffee beans and creating the world’s first strain of spicy tomatoes. From faster racehorses, to salmon with greater levels of omega-3, the current and possible uses of CRISPR technology are genuinely mind-blowing. Yet, the most astonishing function of CRISPR so far has got to be in the field of de-extinction.
A term that sounds like it’s been taken straight from a scene in ‘Jurassic Park’, de-extinction is exactly what it sounds – the revival of extinct species. Already, scientists have been working to bring back the North American passenger pigeon, with the first generation anticipated to hatch next year. Through the use of CRISPR, researchers have manipulated the genes of the bird’s closest living relative: creating hybrids. These hybrids are then bred over generations until an offspring that is genetically identical to the once extinct species is born.
It’s this technique that Harvard bioscience company, Colossal, propose to use in order to bring back the woolly mammoth. The organisation, which has already raised £11m in hopes to achieve this goal, intends to genetically manipulate an Asian elephant’s skin cells. Through the comparison of the original woolly mammoth’s genome, isolated from animals found in the permafrost, Colossal is able to distinguish which parts of the genome are specific to the mammoth, for example, those that encode thick hair and a greater composition of fat. From here, the mammoth’s genome can be implanted into embryos which are either grown in an artificial womb or carried in an Asian elephant surrogate.
If each of these stages is successful, researchers believe that there will be baby mammoths in as early as six years. Considering woolly mammoths died out around 10,000 years ago, why are researchers so persistent to bring them back?
Professor of genetics at Harvard and co-founder of Colossal, George Church, told The Guardian that the company’s ambition is to “make a cold-resistant elephant [that] is going to look and behave like a mammoth.” It is this behaviour that Church talks of which is driving the company’s motivation. Scientists predict that establishing mammoth herds in the Arctic tundra will restore the damaged habitat, for example by pushing down trees to re-establish areas of once-spoiled grassland.
However, not all researchers believe that this method is the most constructive use of time in terms of Arctic restoration. Dr Victoria Herridge, from the Natural History Museum, argues that “the justifications given, the idea that you could geoengineer the Arctic environment using a herd of mammoths, isn’t plausible,” and further claims the 22-month mammoth gestation period and 30-year maturation mean that the scale of the experiment is “enormous.”
Despite differing views on resurrecting the woolly mammoth, it seems we can all agree that the ability to bring a species back from extinction is ground-breaking, giving us exciting possibilities for the future of our planet.
Illustration: Anna Kuptsova