Moms and pups sniff out immune genes

Given how similar newborns can look, forgive parents if they have trouble picking out their bundle of joy from the swaddled masses in a maternity ward. Perhaps they should sniff each one. After all, among animals, many parents and offspring recognize each other by scent.

The major histocompatibility complex (MHC), a cluster of genes important to the immune system, is at the heart of this olfactory ability, suggests a mouse study in the Sept.