RESUMEN

Regional specification is critical for skin development, regeneration, and evolution. The contribution of epigenetics in this process remains unknown. Here, using avian epidermis, we find two major strategies regulate ß-keratin gene clusters. (1) Over the body, macro-regional specificities (scales, feathers, claws, etc.) established by typical enhancers control five subclusters located within the epidermal differentiation complex on chromosome 25; (2) within a feather, micro-regional specificities are orchestrated by temporospatial chromatin looping of the feather ß-keratin gene cluster on chromosome 27. Analyses suggest a three-factor model for regional specification: competence factors (e.g., AP1) make chromatin accessible, regional specifiers (e.g., Zic1) target specific genome regions, and chromatin regulators (e.g., CTCF and SATBs) establish looping configurations. Gene perturbations disrupt morphogenesis and histo-differentiation. This chicken skin paradigm advances our understanding of how regulation of big gene clusters can set up a two-dimensional body surface map.

Asunto(s)

Proteínas Aviares/metabolismo , Factor de Unión a CCCTC/metabolismo , Ensamble y Desensamble de Cromatina , Células Epiteliales/metabolismo , Factores de Transcripción de Tipo Kruppel/metabolismo , Morfogénesis , beta-Queratinas/genética , Animales , Proteínas Aviares/genética , Factor de Unión a CCCTC/genética , Diferenciación Celular , Embrión de Pollo , Cromosomas/genética , Células Epiteliales/citología , Plumas/citología , Plumas/embriología , Plumas/metabolismo , Regulación del Desarrollo de la Expresión Génica , Factor 4 Similar a Kruppel , Factores de Transcripción de Tipo Kruppel/genética , Familia de Multigenes