Mammalian-specific ectodermal enhancers control the expression of <i>Hoxc</i> genes in developing nails and hair follicles
Marc Fernández‐Guerrero, Nayuta Yakushiji‐Kaminatsui, Lucille Lopez‐Delisle, Sofía Zdral, Fabrice Darbellay, Rocío Pérez‐Gómez, Christopher Chase Bolt, Manuel Sánchez‐Martín, Denis Duboule, María A. Ros
Abstract
Significance In this study, we report a unique and necessary function for the HoxC gene cluster in the development of some ectodermal organs, as illustrated both by the hair and nail phenotype displayed by mice lacking the Hoxc13 function and by the congenital anonychia (absence of nails) in full HoxC cluster mutants. We show that Hoxc genes are activated in a colinear manner in the embryonic limb ectoderm and are subsequently transcribed in developing nails and hairs. We identify two mammalian-specific enhancers located upstream of the HoxC cluster, which display an exclusive ectodermal specificity. Individual or combined enhancer deletions suggest that they act in combination to raise the transcription level of several Hoxc genes during hair and nail development.