Dynamic morphogenesis of a pioneer axon in and its regulation by Abl tyrosine kinase.

The fundamental problem in axon growth and guidance is to understand how cytoplasmic signaling modulates the cytoskeleton to produce directed growth cone motility. We here dissect this process using live imaging of the TSM1 axon of the developing wing. We find that the growth cone is almost purely filopodial, and that it extends by a protrusive mode of growth.