Studies on insect physiological active substance-metabolizing cytochrome P450s and their expressional regulation
| Project/Area Number |
16380045
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Applied entomology
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| Research Institution | National Institute of Infectious Diseases |
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Principal Investigator |
TOMITA Takashi National Institute of Infectious Diseases, Department of medical Entomology, Chief, 昆虫医科学部, 室長 (20180169)
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| Co-Investigator(Kenkyū-buntansha) |
KASAI Shinji National Institute of Infectious Diseases, Department of medical Entomology, Senior Researcher, 昆虫医科学部, 主任研究官 (80332360)
KONO Yoshiaki University of Tsukuba, Graduate School of Life and Environmental Sciences, Professor, 大学院・生命環境科学研究科, 教授 (10225386)
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| Project Period (FY) |
2004 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥14,400,000 (Direct Cost: ¥14,400,000)
Fiscal Year 2006: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 2005: ¥5,100,000 (Direct Cost: ¥5,100,000)
Fiscal Year 2004: ¥7,500,000 (Direct Cost: ¥7,500,000)
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| Keywords | cytochrome P450 / insecticide resistance / insect physiological active substances / microarray analysis / gene amplification / overexpression / microsome monooxygenase system / etofenprox / シトクロムP450 / ネッタイイエカ / マイクロアレイ / 遺伝子過剰発現 / アカイエカ |
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| Research Abstract |
We made six highly pyrethroid-resistant strains of Culex pipiens group mosquitoes (Cx.quinquefasciatus, Cx.pipiens pallens, Cx.p.molestus) by the laboratory selection with etofenprox and also obtained the cytochrome P450 cDNAs classified to 62 different molecular species, and finally analyzed the variation of P450 gene expression in larval mosquitoes by oligo-microarray hybridization. The results involved 69 cases of two times up-regulation and 15 cases of down-regulation in a total of 372 cases of comparison for 62 P450 genes and 6 resistant strains with the respective insecticide-susceptible strains. Characteristic patterns of P450 gene overexpression were classified into the following three : (i) two P450 genes were commonly overexpressing in 5 or 6 resistant strains ; (ii) one P450 gene (#P32) was extraordinally expressing in JPP strain of Cx. q. by 48 times ; (iii) one P450 gene was overexpressing in 4 resistant strains by more than two times, moreover the same gene showed basically high transcriptional levels being equivalent to the ribosomal protein subunit 3 (RPS3) gene even in insecticide-susceptible strains. All these P450s are possibly involved in the mechanisms of increased detoxifying mechanisms. On the contrary, no more than two times up-regulation was shown for cytochrome P450 reductase and cytochrome b5 genes in the resistant strains tested. qPCR measurement revealed that P32 gene in JPP mosquitoes was overexpressed by 300 times. Contiguous sequences which are involved in the 13 kb in and around P32 structural gene mostly coincided with a draft sequence of YHB strain from the genome project on Cx. q. No repetitive gene segment of P32 gene sequence or non-coding sequence were recognized in the contiguous sequences, suggesting the size of the amplicon including P32 structural gene is predicted to be over 13 kb.
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Report
(4 results)
Research Products
(2 results)
