Interests

Neurons must be made in the correct proportions to communicate with the appropriate synaptic partners. In the Drosophila visual system, Distal medulla (Dm) inhibitory interneurons are made with distinct, reproducible numbers—from 5 to 800 per optic lobe. These neurons are born from a crescent-shaped neuroepithelium called the Outer Proliferation Center (OPC), which can be subdivided into specific domains based on non-overlapping transcription factor expression. We fate mapped Dm neurons and found that more numerous neural types were born from larger neuroepithelial subdomains, while less numerous subtypes were born from smaller ones. Additionally, morphogen signaling provides a second layer of patterning that subdivides the neuroepithelium into yet smaller domains, which provides more granular control of cell number. Experiments testing the role of proliferation and apoptosis in Dm number suggest that they play a more minor role in this process. Our work describes a novel cell number regulation mechanism.

Funding

BRAIN Initiative Advanced Postdoctoral Career Transition Award to Promote Diversity (K99/R00)