Over the past decades, the extensive use of pyrethroids insecticides for vector control has resulted in the development of insecticide resistance. Cytochrome P450 has been recognized to play a critical role in the metabolic detoxification of insecticides. In the current study, Culex pipiens mosquitoes were collected from Giza Governorate in Egypt and tested for insecticide susceptibility against deltamethrin. First detection of Knockdown resistance gene (Kdr) mutations in field collected mosquitoes was performed. Activities of cytochrome oxidase P450 detoxification enzyme that synchronized with the resistance development, was assessed. Expression profiles of cytochrome P450s and their putative corresponding regulating miRNAs, which was previously reported in Cx. pipiens pallens were evaluated in pyrethroid resistant field-collected Cx. pipiens using RT-qPCR and stem-loop RT-qPCR, respectively. Specific stem-loop reverse transcription primers and forward primers were designed for miRNAs profiling. Our results elucidated the pyrethroid resistance development and revealed its relation to the metabolic and target site modification mechanisms with a first report of L1014F-kdr mutation detection. RT-qPCR results have showed an up-regulation in the expression of the studied P450 transcripts. Negative correlations were found between the expression of P450s and their regulatory miRNAs except for CYP9J35, where positive correlation was found with its corresponding miR-13. Interestingly, our data was the first to detect negative correlation between miR-285 and its putative CYP6Cp1 target gene. These findings highlighted the significance of identifying P450 gene along with regulatory miRNAs as a key mechanism implicated in pyrethroid resistance in field Culex vector population. The elucidation of this mechanism would shed light on the development of insecticide resistance and would help in shaping strategies to combat such vectors.

中文翻译：

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解密Cx中的拟除虫菊酯抗性。pipiens（L）：细胞色素P450的含义；表达谱和调控microRNA。

在过去的几十年中，拟除虫菊酯类杀虫剂广泛用于媒介控制已导致了对杀虫剂的抗性的发展。细胞色素P450被认为在杀虫剂的代谢解毒中起关键作用。在当前的研究中，从埃及吉萨省收集了淡色库蚊，并测试了其对溴氰菊酯的杀虫剂敏感性。首次在现场收集的蚊子中检测了敲低抗性基因（Kdr）突变。评估了与抗性发展同步的细胞色素氧化酶P450解毒酶的活性。细胞色素P450及其推定的相应调节miRNA的表达谱，先前在Cx中已有报道。在拟除虫菊酯抗药性田间采集的Cx中评估了淡黄色的pipiens pallens。分别使用RT-qPCR和茎环RT-qPCR进行的pipiens。设计特定的茎环逆转录引物和正向引物用于miRNA分析。我们的结果阐明了拟除虫菊酯抗性的发展，并首次报道了L1014F-kdr突变检测揭示了其与代谢和靶位点修饰机制的关系。RT-qPCR结果表明，所研究的P450转录本的表达上调。除CYP9J35外，P450的表达与其调节性miRNA之间呈负相关，而CYP9J35与相应的miR-13呈正相关。有趣的是，我们的数据是第一个检测到miR-285及其推定的CYP6Cp1靶基因之间负相关的数据。这些发现强调了鉴定P450基因以及调节性miRNAs的重要性，这是与现场库克斯病菌种群中拟除虫菊酯抗性有关的关键机制。对这种机制的阐明将为杀虫剂抗性的发展提供启示，并有助于制定与这类载体抗衡的策略。