Project/Area Number |
05454506
|
Research Category |
Grant-in-Aid for General Scientific Research (B)
|
Allocation Type | Single-year Grants |
Research Field |
Functional basic dentistry
|
Research Institution | Ohu University School of Dentistry |
Principal Investigator |
MARUI Takayuki Ohu Univ.School of Dentistry Prof., 歯学部, 教授 (40076047)
|
Co-Investigator(Kenkyū-buntansha) |
AMAGAI Yuji Ohu Univ.School of Dentistry Assistant, 歯学部, 助手 (90118373)
|
Project Period (FY) |
1993 – 1994
|
Project Status |
Completed (Fiscal Year 1994)
|
Budget Amount *help |
¥7,200,000 (Direct Cost: ¥7,200,000)
Fiscal Year 1994: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1993: ¥6,200,000 (Direct Cost: ¥6,200,000)
|
Keywords | Taste transduction / Molecular cloning / G-protein / Nucleotide sequencing / Binding study / In situ hybridization / Taste nerve recordings / 味覚 / 味覚情報変換分子機構 / xenopus 卵母細胞 / 味覚受容タンパク |
Research Abstract |
We have investigated on several aspects of taste transduction in the qustatory system of the carp, Cyprinus carpio L., where electrophysiological, biochemical and molecular biological approaches were made. In the molecularcloning study, the partial structures of a multigene family encoding GTP-binding protein expressed inside taste buds were identified. In situ hybridization experiments clearly indicated that the mRNA for the protein is expressed exclusively in taste buds of a barbel. Biochemical studies of taste sensation with radio-labeled amino acids revealed that the results do not always fit to those obtained from electrophysiological nerve recordings and a fraction of the membrane might not be originated only from taste receptive one. However, it is ascertained that extension of this biochemical approach will permit specific identification of taste receptor sites and a better understanding of the mechanisms of interactions of taste stimulus molecules with their receptors. Electrophysiological recordings of taste responses from the facial nerve of the fish wereperformed, as well as from an isolated Xenopus oocyte. We confirmed that there are six receptor mechanisms (sites) relatively independent each others by cross-adaptation (competetion) techniques. However, no obvious result was obtained from the Xenopus oocyte, bacause of a wrong choice of the biological system for transplantation of receptor by genes. These results will lead us to the next fine steps to complete understanding of the transduction and transmission in chemoreception.
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