Maintaining youth in Drosophila neural progenitors.

An important question is how dividing stem cells maintain competence to generate multiple cell types, whereas most other cells become progressively restricted during development. The molecular basis for progenitor competence--or how competence is progressively restricted--has remained mysterious. Recent work has shown that Drosophila neuroblasts and mammalian neural progenitors are more similar than previously appreciated, and provide an excellent model system for using Drosophila genetics to unravel the molecular nature of progenitor competence and how it becomes progressively restricted during development.