Ephrin-As play a rhombomere-specific role in trigeminal motor axon projections in the chick embryo

摘要: In this study, we investigate the possible role of ephrin–Eph signaling in trigeminal motor axon projections. We find that EphA receptors are expressed at higher levels by rhombomere 2 (r2) neurons than r3 chick embryo. Mapping rhombomere-specific projections shows r2 and project to different muscle targets, including mandibular adductor intermandibularis muscles respectively. Ephrin-A5 is these muscles, especially some regions muscle, can cause growth cone collapse both axons vitro. demonstrate vivo overexpression ephrin-A5 or dominant-negative leads a reduction branching r3-derived specifically. Overexpression full-length impairs formation muscle. These findings indicate ephrins their Eph play topographic mapping 3-derived particular.