Adducins regulate morphology and fate of neural progenitors during neocortical neurogenesis

The evolutionary expansion of the mammalian neocortex is mediated by an increase in the proliferative capacity of neural progenitor cells. However, the molecular machinery controlling the proliferation of apical and basal progenitors during neocortical development is still poorly understood. Here we show that the three actin-associated morpho-regulatory adducins (ADD1-3), underlie abundance of basal progenitors in developing mouse and ferret neocortex in vivo and in human cortical organoids. Over expression of adducins in embryonic mouse neocortex increases the number of protrusions of basal progenitors, leading to an increase in their proliferative capacity and neuronal output. Conversely, knock-out of ADD1 in human cortical organoids, which also leads to down-regulation of other adducins, results in reduced proliferation of progenitors and aberrant neurogenesis. Hence, we show that adducins underlie proliferation and fate of neural progenitors, which are key cellular features underlying progression of mammalian neurogenesis.