The actin-cytoskeleton associating protein BASP1 regulates neural progenitor localization in the neural tube.

Brain acid soluble protein 1 (BASP1; previously NAP22 or CAP23) is an actin-associating protein that is highly expressed in the nervous system throughout development. While its roles at the neuromuscular junction and in certain non-neuronal tissues have been previously characterized, its function in the early neural tube is unclear. Using in ovo electroporation in the chicken (Gallus gallus) embryonic neural tube, we show that BASP1 overexpression resulted in the appearance of ectopic neural progenitor cells within the marginal zone of the neural tube. BASP1 knockdown did not affect the position of neural progenitors but did alter the complexity of axons developing from differentiated neurons. This suggests a role for BASP1 in regulating the apical polarity of progenitor cells and axon trajectories from developing neurons.