Abstract

The distribution of color across the body (i.e., color pattern) is a crucial morphological trait involved in survival and reproductive success which varies tremendously both within and between species. Despite their ecological importance, the genetic and developmental mechanisms responsible for the formation and variation of naturally-occurring color patterns have remained a black box. We showed that in deer mice (genus Peromyscus), the formation of a simple bicolor pattern typical of most vertebrates relies on the establishment of an embryonic “pre-pattern” (i.e., the spatial restriction of pigmentation genes) causing regional differences in pigment cell behavior. Moreover, we showed that large adaptive changes in the adult color pattern seen in a derived Peromyscus population are provoked by small accumulating changes in the pre-pattern. These findings laid the groundwork for studying (1) the embryonic origin of pre-patterns in the skin, (2) the molecular control of their formation and (3) the genetic basis of their evolution in other vertebrates groups. To this end, we propose to use analyses of gene expression and function in natural populations of birds displaying a vast array of skin patterns.