Centrosomes Are Required for the Normal Development of the Skin Epithelium

The study investigated the importance of centrosomes in skin epithelium development by conditionally deleting Sas-4, a protein crucial for centrosome formation, in mouse skin epithelium. The absence of SAS-4 resulted in a thinner epidermis, disrupted hair follicle development, and increased cell death associated with elevated p53 levels, starting from embryonic day 12.5. However, epidermal differentiation was largely unaffected. The removal of p53 in centrosome-deficient skin restored normal epidermal and hair follicle development but did not bring back cilia, indicating that the developmental issues were due to the loss of centrosomes, not cilia. This was further supported by the observation that mice lacking Ift88, which is required for cilia but not centrosomes, did not exhibit significant developmental defects. The study concluded that centrosomes are crucial for the proper development of the epidermis and hair follicles through a mechanism that is dependent on p53, and this role is distinct from the function of cilia.