Published on SDB CoRe: Apr 12 2013
Morphogenesis: Cell Movements; Cell Shape Changes
Ectoderm-derived: Ectodermal Placodes
Stage of Development: Embryo
This movie created by computer graphics shows development of the inner ear, an organ important for hearing and balance. This is a chick embryo at HH stage 16 (2.5 days). The ectodermal placode-derived inner ear primordium called the otocyst can be seen adjacent to the hindbrain. Between days 3 and 4 of development (HH stages 20 to 24), the dorsal region of the otocyst starts to expand and the ventral region grows out ventrally. Between days 4 and 5 (HH stages 24 to 27), the dorsal region of otocyst continues its expansion and forms three pouches—the anterior canal pouch (red), posterior canal pouch (yellow), and lateral canal pouch (green). These pouches will form semi-circular canals later in development. During this same time, the dorsal tip of the otocyst grows out to form the endolymphatic duct (purple), and the ventral region elongates and forms the cochlea duct (blue). Between days 5.5 to 6.5 (HH stages 28 to 30) there is a resorption of cells at the center of each pouch where fusion plates form, creating three rings, the semi-circular anterior, posterior, and lateral canals.
Brigande J.V., Kiernan A.E., Gao X., Iten L.E., Fekete D.M. Molecular genetics of pattern formation in the inner ear: do compartment boundaries play a role? PNAS, 2000,97:11700-11706.