The Genetics of Your Hairdo

Have you ever felt cursed by a cowlick or stymied by seemingly-permanent bed head? Rumor has it that even supermodel Claudia Schiffer has a couple of untamed tufts right along her forehead.

She’s got expensive stylists, no doubt, to hide her hair woes. But to make yourself feel better next time you’re lamenting your hair in the mirror, remember this: there are mutant mice who lack a gene called Frizzled-6 who have it much worse. A recent study in Proceedings of the National Academy of Sciences showed how Frizzled-6 directs hairs to make them fall in line and give mice their silky smooth coat. But the study also showed how hairdos go horribly wrong when mice are missing this gene.

Each hair in a mouse’s coat lines itself up through a two-step dance. As hair follicles first start to develop, they’re pointing all over the place. Frizzled-6 takes charge and lays out an overall pattern, nudging hairs so they point roughly from head-to-tail. Later in development, in another process that is independent of Frizzled-6, the hairs line up with their next door neighbors. This refines the direction that the hairs are pointing, giving the mouse an overall slick style that’s easy to manage with a few licks of the tongue.

Mice missing the Frizzled-6 gene, on the other hand, lack an overall plan for their coat. The hairs do their best to line up with their neighbors, but the initial chaos leaves them with a coat full of waves, whorls and tufts pointing every which way. And each mouse winds up with its own personalized pattern of cowlicks in different places, just like what can happen to a lesser degree with regular people like you and me - and Claudia Schiffer.