White mice don’t grow on trees. At least, for now.
It’s often said that in a city, you’re never far from a rat. Today’s UK government figures for the numbers of laboratory animals used annually in England, Scotland and Wales reveals the extent to which researchers, too, are surrounded by rats and other rodents. In all 4 million animals were used, a 9 per cent increase on 2011. Most of these – 3.3 million – were rodents. Some 2200 primates were used, mainly in pharmaceutical safety tests.
The majority of the rodents – 1.77 million mice – were mutant, “knockout” mice: animals with a specific gene turned off, helping scientists to understand what that gene does. “It’s a bit like trying to understand a car engine without a plan – piece by piece you pull parts out and then see how this contributes to the car not working,” says David Adams of the Wellcome Trust Sanger Institute in Cambridge, UK.