1996 Fiscal Year Final Research Report Summary
MORPHOLOGICAL VARIETY OF THE BRANCHIAL CHLORIDE CELLS.
| Project/Area Number |
07640887
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
生物形態・構造
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| Research Institution | KANAGAWA UNIVERSITY |
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Principal Investigator |
OGASAWARA Tsuyoshi KANAGAWA UNIV., BIOLOGY,PROFESSOR, 理学部, 教授 (20167315)
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| Project Period (FY) |
1995 – 1996
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| Keywords | OSMOREGULATION / GILLS / VITAL STAINING / CHLORIDE CELLS / TURNOVER / ION TRANSPORT / MEDAKA / DACE |
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| Research Abstract |
We have observed fish gills with epifluorescent microscopy. DASPEI,a vital staining dye for active mitochondria, revealed three-dimensional features of the gills. These procedures offer us new information that could not obtain by a sectioned preparation. Medaka, Oryzias latipes, are easy to maintain, and show well adaptability to full-strength seawater. We performed fundamental work on MEDAKA.DASPEI identified two types of chloride cells (mitochondria- rich cells ; MRCs) on the gill filaments. In fresh water, the cells were small. The MRCs were large in the seawater-adapted fish. It is noteworthy that the MRCs developed much more in the fish in deionized water. During adaptation to seawater from fresh water, or to fresh water from seawater, we successfully observed two types of the MRCs in the same gills. TUNEL and BrdU techniques, which detect degeneration and generation of the cells, respectively, confirmed morphological turnover of the MRCs during adaptation to different salinity. T
… More
he gills should change direction of salt transport in response to environmental salinity. Two types of MRCs would contribute the change in the transport. Unfortunately, we could not show where the MRCs developed. We recognized many of the follicular-arranged MRCs in the acid-tolerant dace, Triborodon hakonensis in pH3.5. The characteristic feature disappeared when the dace were transferred to fresh water. Similar result was shown when NaCl was added to the acidic environment. Therefore, it is unlikely that the well-developed MRCs in the dace are for the acid-base regulation. Although the MRCs are suggested to be multifunctioned, our results do not seem to agree with the present suggestion. The cells are likdely to change morphologically, when fishes adapted to possible environments including salinity, pH and calcium concentration. However, the MRCs are considered to be unifunctioned ; the cells may contribute only salt transport in any environments. Other parameters would be regulated in the cells of organs rather than the MRCs of the gills. Osmoregulation should be summarized effects of the whole individual animal. It is interesting to study the intestine and kidney in parallel with the gills of the fish. Less
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Research Products
(3 results)
