SELFISH, parasitic bits of DNA that proliferate throughout our genome might play a key role in determining our individuality.
Mobile genetic elements, or “jumping genes”, are genetic parasites whose sole purpose seems to be to copy themselves. Amazingly, jumping genes make up around 95 per cent of our genome, although the vast majority are relics no longer capable of copying themselves. One class, called L1 retrotransposons, make up about 20 per cent of mammalian DNA.
Fred Gage’s team at the Salk Institute for Biological Studies, California, created their own version of a human L1 element and let it loose in cell culture. They found that the…
