ONE piece of so-called “junk” DNA appears to have a surprising role. In voles at least, a particular stretch of non-coding DNA seems to control a male’s fidelity.
Larry Young and Elizabeth Hammock at Emory University in Atlanta, Georgia, bred two strains of prairie voles. Each had different lengths of “microsatellite” DNA in a gene encoding a receptor for the hormone vasopressin. Microsatellites are repetitive DNA sequences which, like all junk DNA, do not code for proteins.
The strains differed in length by just 19 base pairs; a small difference, but enough to change the voles’ behaviour. Males with the…
