Why is this mouse healthy? Scientists know that genomes of mammals share DNA sequences whose function is unknown, but that are perfectly conserved between species. It seems natural to think those sequences must be somehow vital to the organism, since tens of million years of evolution didn't touch them. Yet when they deleted one of them (herein printed under the mice) from the genome of some mice, they found that no apparent side effect happens. What is the role, then, of these sequences?
Read the full story on PLoS Biology.