In contrast to wild type larval brains, transient (2 hour) low-level expression of pros^{Scer\UAS.T:Ivir\HA1} under the control of Scer\GAL4^wor.PA and Scer\GAL80^ts.αTub84B results in the appearance of numerous quiescent neuroblasts 12 hours after induction. After 24 hours of induction many of the quiescent neuroblasts had reactivated proliferation. Expression of low-level pros^{Scer\UAS.T:Ivir\HA1} also advances the timing of NB3-3T neuroblast quiescence. Higher levels of pros expression result in differentiation.