Metabolic pathway to form a chiral chromophore of visual pigment in Insecta
| Project/Area Number |
05640767
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
動物生理・代謝
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| Research Institution | Osaka Kyoiku University |
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Principal Investigator |
SEKI Takafaru Osaka Kyoiku University, Education Assistant profssor, 教育学部, 助教授 (50171327)
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| Co-Investigator(Kenkyū-buntansha) |
ISONO Kunio Tohoku Uiversity, Information Sciences Assistant, 情報科学研究科, 助手 (70124550)
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| Project Period (FY) |
1993 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1994: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1993: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | Insect / Visual pigment chromophore / Chirality / 3-Hydroxyretinal / Drosophila melanogaster / Optical resolution / Metabolic pathway / High performance liquid chromatography / 3-ヒドロキシレチナール / 光学分割カラム |
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| Research Abstract |
1. The distribution of optical isomers of 3-hydroxyretinal as s chromophore of visual pigments in Insecta
Chirality of 3-hydroxyretinal (3-OH-RAL) in the compound eyes of insects that use 3-OH-RAL as the chromophore of visual pigment was analyzed by using a chiral column HPLC.The results show that only a (3R) -enantiomer of 3-OH-RAL is used by insects belonging to orders Odonata, Hemiptera, Neuroptera, Lepidoptera and suborders Nematocera and Brachycera of Diptera. These insects may use (3R) -3-OH xanthophylls produced by plants as a direct precursor of the chromophore 3-OH-RAL. On the contrary, flies belonging to the suborder Cyclorrhapha of Diptera use the (3S) -3-OH-RAL as the chromophore of visual pigment. These flies must have some metabolic activities to form the (3S) -3-OH-beta-end group.
2. Formation of the (3S) -3-0H-RAL by Drosophila melanogaster
Yellow corn grits used to rear D.melanogaster contain only xanthophylls (lutein, zeaxanthin and chryptoxanthin) but no retinoids.
When the D.melanogaster is reared on a yeast medium containing the alltrans retinal or beta-carotene as the retinoid source, it forms the 3-OH-RAL by a hydroxylation of the beta-end group. The chirality of the 3-OH-RAL produced was examined, and found that the (3S) -enantiomer is produced at a high specificity : 95% or 90% of all-trans 3-OH-RAL originating from the retinal or beta-carotene, respectively. The ratio of (3S) -enantiomer in the 11-cis isomer was 100% or 95% starting from the retinal or beta-carotene, respectively. These results suggest the difference of metabolic pathway to form visual pigment chromophore starting from retinoid or carotenoid.
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Report
(3 results)
Research Products
(10 results)
