Figure 2.

Expression of Notch signaling components in the skin. (A) Schematic representation of the murine skin showing the expression pattern of components of the Notch signaling pathway. The epidermis is a stratified squamous epithelium that is composed of multiple cell layers. The basal cell layer localizes to the basement membrane (BM) and consists mostly of TA cells intermingled with a few stem cells. The basal cell layer gives rise first to the spinous layer followed by the granular layer and then the cornified layer. The expression of Notch receptors and ligands is indicated. (B) Schematic depiction of Notch receptor and ligand expression in the hair follicle. Notch1 is expressed in the matrix and pre-cortex, Notch2 in the upper portion of the pre-cortex and inner root sheath, and Notch3 in the hair shaft. Jagged1 is expressed in a small portion of the matrix and in the pre-cortex. Jagged2 is expressed in the cells adjacent to the dermal papilla and in the outer root sheath. (Image based on data from Watt et al. 2008.)