Development
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Nuclei are aggregates of neurons distributed in the central nervous system and are fundamental functional units that share anatomical and physiological features. Despite their importance, the cellular basis that leads to nucleogenesis is only poorly understood. Using exo utero electroporation with an enhanced yellow fluorescent protein (EYFP) gene, we show that the precerebellar neurons derived from the lower rhombic lip (lRL) undergo multiple migration steps to form nuclei. ⋯ Before forming the clusters, EYFP-labelled neurons begin to migrate radially towards the ventricle in close apposition to nestin-positive radial fibres, and then they aggregate as they detach from the fibres. Inhibition of cadherin function in ECN and LRN progenitors caused ipsilateral formation of the ECN and LRN, implying that the transition of their migration from tangential to radial involves a cell-intrinsic mechanism. These observations suggest that nucleogenesis of precerebellar neurons is a result of multi-phasic migration, and that ventricle-directed radial glia-guided migration is a key step for nucleogenesis.