Sprouty genes are essential for the normal development of epibranchial ganglia in the mouse embryo

► Sprouty gene deletion in mouse embryos cause multiple defects in epibranchial ganglia. ► Both epibranchial placodes and neural crest cells are affected. ► Sprouty gene function is required in the pharyngeal ectoderm and endoderm. ► Hyperactive FGF8 signalling is in part responsible for these defects.