Department of Medical Entomology, National Institute of Infectious Diseases, Shinjuku-ku, Tokyo, Japan.
Insect Biochem Mol Biol. 2010 Feb;40(2):146-52. doi: 10.1016/j.ibmb.2010.01.006. Epub 2010 Jan 18.
JPal-per strain of Culex quinquefasciatus exhibits extremely high resistance against pyrethroids in larvae, though the resistance is greatly lower in adults. Increased microsome monooxygenase metabolism is one of the major factors of the larval resistance in this strain. We cloned 46 novel cytochrome P450 cDNAs from JPal-per strain. An oligonucleotide microarray was designed for the novel 46 genes plus 16 previously reported P450 genes along with other non-P450 gene probes. Of these, five P450 genes were upregulated (>2.5-fold) in JPal-per larvae as compared with a susceptible strain. The expression ratios for the highest three among the five P450 genes screened in the microarray analysis, CYP9M10, CYP4H34 and CYP6Z10, were further validated by qPCR as 264-, 8.3-, and 3.9-fold, respectively. In JPal-per, the transcription levels of CYP9M10 and CYP4H34 showed a similar stage-dependent pattern as a high expression level during the larvfrom Ogasawara Islands in Japanal stage dramatically decreases in the adult stage. This larval specific overexpression manner of the two genes was consistent with the characteristic of stage-dependent resistance of JPal-per strain previously reported, suggesting that the two P450s, CYP9M10 and CYP4H34, are involved in pyrethroid detoxification in JPal-per strain.
日本伊蚊 JP 品系对拟除虫菊酯的幼虫表现出极高的抗性，尽管在成蚊中抗性要低得多。微体单加氧酶代谢增加是该品系幼虫抗性的主要因素之一。我们从 JP 品系中克隆了 46 种新的细胞色素 P450 cDNA。设计了一个寡核苷酸微阵列，用于新的 46 个基因加上之前报道的 16 个 P450 基因以及其他非 P450 基因探针。与敏感品系相比，JP 品系幼虫中有 5 种 P450 基因上调（>2.5 倍）。在微阵列分析中筛选出的 5 种 P450 基因中，最高的 3 种基因（CYP9M10、CYP4H34 和 CYP6Z10）的表达比率通过 qPCR 进一步验证分别为 264 倍、8.3 倍和 3.9 倍。在 JP 品系中，CYP9M10 和 CYP4H34 的转录水平表现出类似的发育阶段依赖性模式，即在幼虫期表达水平较高，而在成虫期则急剧下降。这两种基因的幼虫特异性过表达方式与之前报道的 JP 品系对拟除虫菊酯的发育阶段依赖性抗性特征一致，表明这两种 P450 酶（CYP9M10 和 CYP4H34）参与了 JP 品系对拟除虫菊酯的解毒作用。
