Abstract
MicroRNAs (miRNAs) have been implicated in regulating various aspects of animal development, but their functions in neurogenesis are largely unknown. Here we report that loss of miR-9a function in the Drosophila peripheral nervous system leads to ectopic production of sensory organ precursors (SOPs), whereas overexpression of miR-9a results in a severe loss of SOPs. We further demonstrate a strong genetic interaction between miR-9a and senseless (sens) in controlling the formation of SOPs in the adult wing imaginal disc. Moreover, miR-9a suppresses Sens expression through its 3' untranslated region. miR-9a is expressed in epithelial cells, including those adjacent to SOPs within proneural clusters, suggesting that miR-9a normally inhibits neuronal fate in non-SOP cells by down-regulating Sens expression. These results indicate that miR-9a ensures the generation of the precise number of neuronal precursor cells during development.
