Fine structural aspects of the inner ear in relation to the incremental growth of otoliths in fishes
| Project/Area Number |
61480065
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
General fisheries
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
YAMADA Juro Professor; Faculty of Fisheries, Hokkaido Univ., 水産学部, 教授 (60001575)
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| Co-Investigator(Kenkyū-buntansha) |
SHIMIZU Motohiro Assist. Prof.; Faculty of Fisheries, Hokkaido Univ., 水産学部, 講師 (80002088)
MUGIYA Yasuo Assoc. Prof.; Faculty of Fisheries, Hokkaido Univ., 水産学部, 助教授 (50001615)
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| Project Period (FY) |
1986 – 1987
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| Project Status |
Completed (Fiscal Year 1987)
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| Budget Amount *help |
¥6,500,000 (Direct Cost: ¥6,500,000)
Fiscal Year 1987: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1986: ¥6,000,000 (Direct Cost: ¥6,000,000)
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| Keywords | fish otolith / early development / saccular cells / apocrine secretion / microvillous secretion / matrix proteins, calcium binding capacity / Ca結合能 / アミノ酸組成 / 内耳 / 感覚斑 / 小嚢上皮 / 有機基質 |
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| Research Abstract |
This research project aimed to clarify cellular contributions of the membraneous rabyrinth to the incremental growth of otoliths in fishes from fine structural and biochemical viewpoints. Major subjects investigated and the results obtained are summarized as follows:
1. Otolith development in medaka (Oryzias latipes) embryos: The otolith rudiment first appears in the otic vesicle of 2-day embryos as an assemblage of many minute spherules (primordia) measured about 1 um in diameter, close to the presumptive macula. The spherules are observed to originate from apocrine type secretory protrusions of macular cells which are not yet differentiated to sensory cells. The spherules are agglutinated to form the otolith core in 3-day embryos. Accretional growth of the otolith follows around the otolith core by depositing fine filaments secreted through microvilli of the perimacular epithelial cells.
2. Ultrastructure of the saccular wall in juvenile tilapia (Orechromis niloticus): Two types of sec
… More
retion were observed in the cells of the saccular wall; apocrine type secretion of macular cells and liberation of vesicles at the distal end of microvilli of perimacular cells, the former seemed to contribute to the gelatinous layer of the otolithic membrane and the latter to the subcupular meshwork, filaments of which were incorporated into the otolith as the organic constituent. Perimacular cells of the transitional epithelium of the saccular wall, characterized by abundant microvilli, were observed to be actively involved in the otolith growth.
3. Biochemical properties of matrix proterns of otoliths in tilapia (Orechromis niloticus): Proteins were extracted with 10 % EDTA from the otoliths. The EDTA- extracted proteins were fractionated into FI-FV by ion-exchange chromatography. PAGE and SDS-PAGE patterns showed that each fraction contained several proteins of 22-185 KDa. Proteins of FIII,IV and V, particularly of FV, were rich in acidic amino acids such as Glu and Asp, and showed the calcium binding capacity. Proteoglycans were found to be contained in FV. Histochemical tests applied to the saccular wall suggested that proteoglycans are actively produced in the perimacular cells at midnight. Less
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Report
(2 results)
Research Products
(12 results)
