show Abstracthide AbstractLong non-coding RNAs (lncRNAs) are a diverse category of transcripts with poor conservation and have expanded greatly in primates, particularly in their brain. We identified a lncRNA, which has acquired 16 microRNA response elements (MREs) for miR-143-3p in the Catarrhini branch of primates. This lncRNA termed LncND (neuro-development) gets expressed in neural progenitor cells and then declines in mature neurons. Binding and release of miR-143-3p, by LncND, can control the expression of Notch. Its expression is highest in radial glia cells in the ventricular and outer subventricular zones of human fetal brain. Down-regulation of LncND in neuroblastoma cells reduced cell proliferation and induced neuronal differentiation, an effect phenocopied by miR-143-3p over-expression and supported by RNA-seq analysis. These findings support a role for LncND in miRNA-mediated regulation of Notch signaling in the expansion of the neural progenitor pool of primates and hence contributing to the rapid growth of the cerebral cortex. Overall design: SHSY5Y cells treated either with miR-143-3p mimic or 100 nM of siRNA specific for LncND were sequenced on NextSeq500 platform. Scrambled siRNA or miRNA sequences were used as a negative control.