Prospero prevents lineage-specific loss and gain by regulating cyclin E and mitosis during Drosophila neurogenesis.

Loss of Prospero in Drosophila neuroblasts causes lineage-specific cell cycle defects linked to cyclin E misregulation and mitotic arrest, not dedifferentiation.

• Why it matters: Understanding Prospero's role is crucial because its loss was previously thought to induce dedifferentiation into stem cells, but the actual mechanisms remain unclear, impacting knowledge of neural development.
• What they did: The study examined prospero loss-of-function mutants, analyzing gene expression, axon projection, cell division, and chromatin binding, revealing lineage-dependent division failure and cell cycle arrest.
• The result: Findings show that prospero mutants do not dedifferentiate into stem cells but exhibit impaired division and mitotic arrest associated with cyclin E misregulation, clarifying Prospero's role in neurogenesis regulation.