Formation of the inner ear during embryonic and larval development of the cichlid fish (Oreochromis mossambicus).
BACKGROUND
The vertebrate inner ear comprises mineralized elements, namely the otoliths (fishes) or the otoconia (mammals). These elements serve vestibular and auditory functions. The formation of otoconia and otoliths is described as a stepwise process, and in fish, it is generally divided into an aggregation of the otolith primordia from precursor particles and then a growth process that continues throughout life.


RESULTS
This study was undertaken to investigate the complex transition between these two steps. Therefore, we investigated the developmental profiles of several inner ear structural and calcium-binding proteins during the complete embryonic and larval development of the cichlid fish Oreochromis mossambicus in parallel with the morphology of inner ear and especially otoliths. We show that the formation of otoliths is a highly regulated temporal and spatial process which takes place throughout embryonic and larval development.


CONCLUSIONS
Based on our data we defined eight phases of otolith differentiation from the primordia to the mature otolith.
a Zoological Institute , University of Stuttgart-Hohenheim , Stuttgart , Germany.|b Department of Biology , Mount Saint Vincent University , Halifax , Nova Scotia , Canada.
Jochen
J
Weigele
b Department of Biology , Mount Saint Vincent University , Halifax , Nova Scotia , Canada.
Tamara A
TA
Franz-Odendaal
a Zoological Institute , University of Stuttgart-Hohenheim , Stuttgart , Germany.
Reinhard
R
Hilbig
D000818:Animals; D002135:Calcium-Binding Proteins / Q000096:biosynthesis; D004625:Embryo, Nonmammalian / Q000196:embryology*; D047108:Embryonic Development / Q000502:physiology*; D029941:Fish Proteins / Q000096:biosynthesis; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D010037:Otolithic Membrane / Q000196:embryology*; D017210:Tilapia / Q000196:embryology*
D002135:Calcium-Binding Proteins; D029941:Fish Proteins
Otolith; gene expression; matrix protein; mineralized tissues; primordia