Special skin cells get pigments

Skin coloration comes from melanocytes, which donate pigment to epithelial cells. Now, findings from Lorin Weiner, Rong Han, Janice Brissette (Massachusetts General Hospital, Charlestown, MA), and colleagues reveal that color is given out selectively to the dedicated skin cells that request it.

Since melanocytes are the givers of melanin, they've been the focus of studies on coloration. “But we are now showing that epithelial cells tell the melanocytes what to do,” says Brissette. “It's analogous to a child's coloring book. Pigment recipients collectively form the outline of the picture, where the pigments should be placed. And the melanocytes color in the picture.”

Brissette's group is interested in a transcription factor called Foxn1 and its role in the skin. For functional studies, they created mice whose skin precursor cells made extra Foxn1. The mice developed...