In vitro expansion of immature melanoblasts and their ability to repopulate melanocyte stem cells in the hair follicle.

Elucidation of the molecular mechanisms underlying stem cell regulation is of great importance both for basic biology and for clinical applications. Melanocyte stem cells (MSCs) are an excellent model in which to study the molecular basis of stem cell regulation, as the genetic alterations involved in the maintenance of the stem cells are readily identifiable by a premature hair graying phenotype. Research on MSCs has been hampered by the lack of a reliable system to assay their function.

Molecular characterization of melanocyte stem cells in their niche.

Emerging evidence from stem cell (SC) research has strengthened the idea that SC fate is determined by a specialized environment, known as the SC niche. However, because of the difficulty of identifying individual stem cells and their surrounding components in situ, the exact mechanisms underlying SC regulation by the niche remain elusive. To overcome this difficulty, we employed melanocyte stem cells (MSCs), which allow the identification of individual SCs in the niche, the lower permanent portion of the hair follicle (HF).