Quiescent melanocytes form primary cilia.

We show, for the first time, that melanocytes can form a primary cilium in vitro, corresponding to an immotile or sensory cilium. Such cilia are observed when melanocytes reach confluence or when medium nutrient levels are insufficient. This observation should greatly improve our understanding of the signal transduction processes potentially occurring in these cells during embryonic development, homeostasis in adulthood and melanomagenesis.