Multiciliated cells are abundant in the epithelial surface of different tissues, 
including cells lining the walls of the lateral ventricles in the brain and the 
airway epithelium. Their main role is to control fluid flow and defects in their 
differentiation are implicated in many human disorders, such as hydrocephalus, 
accompanied by defects in adult neurogenesis and mucociliary disorder in the 
airway system. Here we show that Mcidas, which is mutated in human mucociliary 
clearance disorder, and GemC1 (Gmnc or Lynkeas), previously implicated in cell 
cycle progression, are key regulators of multiciliated ependymal cell generation 
in the mouse brain. Overexpression and knockdown experiments show that Mcidas 
and GemC1 are sufficient and necessary for cell fate commitment and 
differentiation of radial glial cells to multiciliated ependymal cells. 
Furthermore, we show that GemC1 and Mcidas operate in hierarchical order, 
upstream of Foxj1 and c-Myb transcription factors, which are known regulators of 
ependymal cell generation, and that Notch signaling inhibits GemC1 and Mcidas 
function. Our results suggest that Mcidas and GemC1 are key players in the 
generation of multiciliated ependymal cells of the adult neurogenic niche.