Clinical Snippets

Ptch1 is critical for the appropriate spatiotemporal activation of the Hedgehog signaling pathway during development; however, functional redundancy of the Ptch1 and Ptch2 receptors in basal cells of adult and embryonic mouse epidermis remains unknown. In three mouse models, Adolphe and colleagues showed that loss of both Ptch1 and Ptch2 results in a lack of HF and sebaceous gland fate specification as well as in a complete absence of interfollicular epidermis stratification and differentiation. Thus, these two factors are not completely redundant and either Ptch1 or Ptch2 activity is essential for epidermal lineage specification.