The choreography of development: RNA localization across time and space

RNA localization is a conserved mechanism essential for development. By linking transport, anchoring and local translation, cells can achieve precise spatial control of gene expression. This coordinated regulation also allows developing, polarized cells to rapidly translate mRNAs in response to local cues. mRNA localization relies on cis-elements within transcripts, trans-acting RNA-binding proteins and active transport by cytoskeletal motors, vesicles and organelles. Across evolution - from Drosophila to mammals - localized transcripts govern embryonic patterning, cell polarity and fate specification. Within the developing nervous system, polarized radial glia, neurons, astrocytes and oligodendrocytes rely on mRNA localization for morphogenesis and circuit formation. Advances in omics and imaging technologies are shedding light on the function of localized transcriptomes in these different models. This Review highlights discoveries across model systems that collectively reveal diverse RNA localization and local translation mechanisms that orchestrate development across time and space.