Melanoblasts' Proper Location and Timed Differentiation Depend on Notch/RBP-J Signaling in Postnatal Hair Follicles

This study demonstrated that the Notch/RBP-J signaling pathway played crucial roles in the postnatal development of the melanocyte lineage in hair follicles. By conditionally ablating the RBP-J gene in melanocytes and using the Dct-lacZ reporter transgene, researchers found that Notch/RBP-J-deficient melanoblasts were fewer in number and improperly located within the hair follicle. Notch signaling was essential to prevent premature differentiation of melanocyte stem cells and melanoblasts, ensuring their proper placement in the outer root sheath and hair matrix. These findings highlighted previously unrecognized functions of Notch signaling in maintaining melanocyte lineage homeostasis.