Andl T, Reddy ST, Gaddapara T, Millar SE
Dev Cell. 2002 2 (5)
Hair follicle morphogenesis is initiated by a dermal signal that induces the development of placodes in the overlying epithelium. To determine whether WNT signals are required for initiation of follicular development, we ectopically expressed Dickkopf 1, a potent diffusible inhibitor of WNT action, in the skin of transgenic mice. This produced a complete failure of placode formation prior to morphological or molecular signs of differentiation, and blocked tooth and mammary gland development before the bud stage. This phenotype indicates that activation of WNT signaling in the skin precedes, and is required for, localized expression of regulatory genes and initiation of hair follicle placode formation.
MeSH Terms (35)Animals Base Sequence beta Catenin Cell Differentiation Cell Division Cytoskeletal Proteins DNA-Binding Proteins Edar Receptor Epidermal Cells Female Gene Expression Regulation, Developmental Hair Hair Follicle Intercellular Signaling Peptides and Proteins In Vitro Techniques Lymphoid Enhancer-Binding Factor 1 Mammary Glands, Animal Membrane Proteins Mice Mice, Inbred C57BL Mice, Transgenic Phenotype Proteins Proto-Oncogene Proteins Receptors, Ectodysplasin Receptors, Tumor Necrosis Factor RNA, Messenger Signal Transduction Skin Physiological Phenomena Tooth Abnormalities Trans-Activators Transcription Factors Up-Regulation Wnt Proteins Zebrafish Proteins