From shared lineage to distinct functions: the development of the inner ear and epibranchial placodes.
The inner ear and the epibranchial ganglia constitute much of the sensory system in the caudal vertebrate head. The inner ear consists of mechanosensory hair cells, their neurons, and structures necessary for sound and balance sensation. The epibranchial ganglia are knots of neurons that innervate and relay sensory signals from several visceral organs and the taste buds. Their development was once thought to be independent, in line with their independent functions. However, recent studies indicate that both systems arise from a morphologically distinct common precursor domain: the posterior placodal area. This review summarises recent studies into the induction, morphogenesis and innervation of these systems and discusses lineage restriction and cell specification in the context of their common origin.
Ladher
Raj K
RK
RIKEN Center for Developmental Biology, Chuoku, Kobe 650-0047, Japan. raj-ladher@cdb.riken.go.jp
O'Neill
Paul
P
Begbie
Jo
J
D000818:Animals; D019521:Body Patterning; D001934:Branchial Region / Q000196:embryology / Q000294:innervation; D002642:Chick Embryo; D007758:Ear, Inner / Q000196:embryology* / Q000294:innervation*; D004627:Embryonic Induction; D005346:Fibroblast Growth Factors / Q000502:physiology; D017950:Ganglia, Sensory / Q000196:embryology*; D053403:Lateral Line System / Q000196:embryology / Q000294:innervation; D051379:Mice; D008954:Models, Biological; D055495:Neurogenesis; D015398:Signal Transduction; D015027:Zebrafish / Q000196:embryology
D005346:Fibroblast Growth Factors