Development of the dorsal ramus of the spinal nerve in the chick embryo: A close relationship between development and expression of guidance cues

► We examined the dorsal ramus development with thick sections stained by axonin-1. ► Motor axons showed a “waiting period” before entering the myotome. ► Chick SEMA3A and FGF8 were both expressed in the myotome at early stages. ► Motor axons responded to both SEMA3A-induced repulsion and FGF8-induced attraction. ► DRG axons responded to SEMA3A-induced repulsion but not to FGF8-induced attraction.