First they cloned Dolly the sheep. Now they’re targeting grey squirrels

For 150 years they have wreaked havoc on Britain’s woods and wildlife, but the destructive reign of the grey squirrel could soon be over — ended by DNA editing to ensure that all future females are born infertile.
Researchers at the Roslin Institute, the genetics laboratory renowned for its 1996 creation of Dolly the Sheep, the world’s first mammal cloned from an adult cell, want to create gene-edited squirrels for eventual release into the wild.