0497 Periderm without IRF6: To be or not to be

Epidermal morphogenesis starts with the delamination of ectoderm-derived epithelial cells from the basal layer to form a flat layer of periderm cells. Subsequent epidermal layers are formed under the periderm, which is shed right before birth after terminal differentiation is completed. Terminal epidermal differentiation is impaired in the absence of the transcription factor Interferon Regulatory Factor 6 (IRF6) as neonatal Irf6-deficient murine embryos lack the granular and cornified layers. These embryos also exhibit oral epithelium defects, with the presence of tissue-tissue fusions due to a presumptive loss of oral periderm/function.