2004 Fiscal Year Final Research Report Summary
Photoreception in skin pigment cells.
| Project/Area Number |
14540631
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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 |
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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 MRDICINE, ASSOSIATE PROFFESSOR, 医学部(平成15年3月退職), 助教授 (80002244)
YAMADA Keiko SAPPORO MEDICAL UNIVERSITY, SCHOOL OF MRDICINE, ASSOSIATE PROFFESSOR, 保健医療学部, 助教授 (80045541)
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| Project Period (FY) |
2002 – 2004
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| Keywords | photo response / pigment cell / melanocyte / opsin / transducin / onion fly / phototaxis / 走光性 |
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| Research Abstract |
Animal body skin functions as a sensor of changing environmental factors. In skins of poikilothermal vertebrates, various pigment cells respond to visible light directly, resulting in color change of the body. These pigment cells are considered to be one of the non-visual photo systems. However, there is little evidence to show whether melanocytes in homeothermal vertebrates respond to visible light or not.
We have found the expression of opsin mRNA and transducin (Gt) mRNA in murine cultured melanocytes, however, the roles of these molecules remain largely unknown to date. We examined the effects of irradiation with visible light (blue-green LED, 505nm) or with UVA (black light, 365nm) on murine melanocytes. At 24h after irradiation (2.7-5.4J/cm^2) of melanocytes, the expression level of opsin mRNA or GtmRNA was compared with those of non-irradiated cells. The opsin mRNA increased with visible light and decreased with UVA light. Contrarily, the irradiation with visible light did not significantly affect Gt expression. Cell motilities of melanocyte evaluated by assay of cell locomotion (wounding assay) increased after visible light irradiation.
In the onion fly, Delia antiqua, the eclosion rhythm can be entrained to thermoperiod or photoperiod. However, it is not clear how these signals are received in larvae of the fly. We observed larval responses to light which is irradiated by various types of LED (250μW/cm^2). The larvae exhibited negative phototaxis when we used red (644nm), yellow (590nm), yellow-green (574nm), green (567nm), blue-green (500nm), blue (470nm), Purple (405nm) or ultraviolet A (395nm) LED as a light source. The maximum response was obtained at 505nm-irradiation. Expression analysis by RT-PCR and 3'RACE PCR in whole body of larvae of onion fly showed the presence of opsin mRNA. The amino acid sequence deduced from the PCR product was found to have 95% sequence homology with Rh1 opsin of the fruit fly, Drosophila.
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