A critical first step in the formation of the nervous system is the partitioning of the anterior ectoderm into different domains. The neural domain of the ectoderm will form the central nervous system and the neural crest will give rise to the peripheral nervous
system. The mechanisms ensuring proper cell fate commitment, and rate of
differentiation in the anterior ectoderm remain poorly understood. Here, we find that
expression of a pluripotent microRNA family, miR-302, is maintained in the neural crest
and neural tube, suggesting a role in cell fate specification during formation of the
nervous system. Using single-cell mRNA and ATAC sequencing to interrogate the paths
that cells take during specification of the ectoderm, we find acceleration of
developmental timing and a failure of peripheral neuronal differentiation upon miR-302
deletion. Expression of miR-302 is differentially regulated by enhancers in progenitors
within each domain of the ectoderm, consistent with a dynamic regulatory role for miR-
302 in cell fate specification. Additionally, we find that miR-302 controls metabolism and proliferation by targeting genes that promote glycolytic flux. Taken together our results suggest that miR-302 coordinates cell fate specification, cellular metabolism, and proliferation in multipotent progenitors of the developing peripheral and central nervous system.