| Project/Area Number |
11640683
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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 |
動物生理・代謝
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| Research Institution | SAPPORO MEDICAL UNIVERSITY, SCHOOL OF MEDICINE |
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Principal Investigator |
MIYASHITA Yoko SAPPORO MEDICAL UNIVERSITY, SCHOOL OF MEDICINE, ASSISTANT PROFFESSOR, 医学部, 講師 (60045549)
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| Co-Investigator(Kenkyū-buntansha) |
MORIYA Tsuneo SAPPORO MEDICAL UNIVERSITY, SCHOOL OF MEDICINE, ASSOSIATE PROFFESSOR, 医学部, 助教授 (80002244)
浅見 行一 札幌医科大学, 医学部, 教授 (90159385)
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| Project Period (FY) |
1999 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥3,900,000 (Direct Cost: ¥3,900,000)
Fiscal Year 2001: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 2000: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1999: ¥3,100,000 (Direct Cost: ¥3,100,000)
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| Keywords | Xenopus tadpole / melanophore / melanocyte / rhodpsin / melanopsin / light-sensitive / transducin / マウスメラノサイト / ヒトメラノサイト / 光反応性 / 色素胞運動 |
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| Research Abstract |
Pigment cells in animal skin are likely to be one of the non-visual photo systems because various pigment cells respond to light directly, resulting in color change of the animal body.
We ascertained that RT-PCR using rhodopsin specific primers showed the expression of rhodopsin mRNA, in addition to melanopsin (Provencio et al, 1998), in the Xenopus tail fin where photo-sensitive melanophores exist. We consider that rhodopsin and melanopsiri play different roles in the process of photo-response: rhodopsin is probably involved in the aggregation of melanosomes whereas melanopsin is involved in the dispersion. We tried to detect G proteins involved in the photo transduction in melanophores of Xenopus tail fin. RT-PCR using Gta specific primers showed the expression of Gta mRNA and the sequence of the amplified DNA was homologous to the corresponding portion of the sequence of Xenopus rod transducin. We have found the existence of Gi, Gq and Rho small G protein in Xenopus tail fin. Further investigations are needed to know which G protein couples with the two types of opsin, and what molecule is the effector of the G protein.
In addition to pigment cells of lower vertebrates, we confirmed the expression of opsin mRNA in melanocyte, a pigment cell of higher vertebrates. Murine and human cultured melanocytes express opsin mRNA and contain a protein which immunoreacts with anti-rhodopsin antibody. In murine skin tissue, we also found the expression of opsin mRNA. Furthermore, we ascertained the expression of Gta mRNA in murine melanocyte. The functional properties of the opsin and transducin are very interesting because there is no evidence of responses to visual light in mammalian melanocytes. This will provide additional insight into photoreception systems in animal skin.
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