TY - JOUR
T1 - The morphogenic features of otoconia during larval development of Cynops pyrrhogaster, the Japanese red-bellied newt
AU - Steyger, Peter S.
AU - Wiederhold, Michael L.
AU - Batten, Jeffrey
PY - 1995/4
Y1 - 1995/4
N2 - Otoconia are calcified protein matrices within the gravity-sensing organs of the vertebrate vestibular system. Mammalian otoconia are barrel-shaped with triplanar facets at each end. Reptilian otoconia are commonly prismatic or fusiform in shape. Amphibians have all three otoconial morphologies, barrel-shaped otoconia within the utricle, with prismatic and fusiform otoconia in the saccule. Scanning electron microscopy revealed a sequential appearance of all three otoconial morphologies during larval development of the newt, Cynops pyrrhogaster. The first otoconia appear within a single, developing otolith, and some resemble adult barrel-shaped otoconia. As the larvae hatch, around stages 39-42, the single otolith divides into two anatomically separate regions, the utricle and saccule, and both contain otoconia similar to those seen in the single otolith. Throughout development, these otoconia may have variable morphologies, with serrated surfaces, or circumferential striations with either separated facets or adjacent facets in the triplanar end-regions. Small fusiform otoconia occur later, at stage 51, and only in the saccule. Prismatic otoconia appear later still, at stage 55, and again only in the saccule. Thus, although prismatic otoconia are the most numerous in adult newts, it is the last vestibular otoconial morphology to be expressed.
AB - Otoconia are calcified protein matrices within the gravity-sensing organs of the vertebrate vestibular system. Mammalian otoconia are barrel-shaped with triplanar facets at each end. Reptilian otoconia are commonly prismatic or fusiform in shape. Amphibians have all three otoconial morphologies, barrel-shaped otoconia within the utricle, with prismatic and fusiform otoconia in the saccule. Scanning electron microscopy revealed a sequential appearance of all three otoconial morphologies during larval development of the newt, Cynops pyrrhogaster. The first otoconia appear within a single, developing otolith, and some resemble adult barrel-shaped otoconia. As the larvae hatch, around stages 39-42, the single otolith divides into two anatomically separate regions, the utricle and saccule, and both contain otoconia similar to those seen in the single otolith. Throughout development, these otoconia may have variable morphologies, with serrated surfaces, or circumferential striations with either separated facets or adjacent facets in the triplanar end-regions. Small fusiform otoconia occur later, at stage 51, and only in the saccule. Prismatic otoconia appear later still, at stage 55, and again only in the saccule. Thus, although prismatic otoconia are the most numerous in adult newts, it is the last vestibular otoconial morphology to be expressed.
KW - Biomineralization
KW - Extracellular matrix
KW - Morphogenesis
KW - Otoconia
KW - Vestibular
UR - http://www.scopus.com/inward/record.url?scp=0028948694&partnerID=8YFLogxK
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U2 - 10.1016/0378-5955(95)00013-T
DO - 10.1016/0378-5955(95)00013-T
M3 - Article
C2 - 7642456
AN - SCOPUS:0028948694
SN - 0378-5955
VL - 84
SP - 61
EP - 71
JO - Hearing Research
JF - Hearing Research
IS - 1-2
ER -