Entomology Laboratory, Division of Parasitology, Indian Veterinary Research Institute, Izatnagar, Bareilly, 243122, U.P., India.
Entomology Laboratory, Division of Parasitology, Indian Veterinary Research Institute, Izatnagar, Bareilly, 243122, U.P., India.
Ticks Tick Borne Dis. 2021 Mar;12(2):101610. doi: 10.1016/j.ttbdis.2020.101610. Epub 2020 Nov 26.
Cytochrome P450 monooxygenases mediated metabolic detoxification has been recognized as one of the mechanisms involved in resistance to pyrethroids, which is a class of pesticides that includes acaricides such as deltamethrin. Several cytochrome P450 (CYP) genes were identified in arthropod pests which are upregulated in response to exposure to pesticides used as acaricides. However, to date, limited information is available with respect to CYP genes and their response to acaricide exposure in ticks. We cloned and sequenced four CYP genes, the CYP41, CYP3006G8, CYP319A1 and CYP4W1 from reference susceptible IVRI-I strain of Rhipicephalus microplus. The expression pattern of the genes was investigated using qPCR in reference susceptible IVRI-I, pyrethroid-resistant IVRI-IV and multi-acaricide resistant IVRI-V strains. The effect of a single exposure of deltamethrin, at a concentration of 2600 μg/mL and 299.7 μg/mL on IVRI-IV and IVRI-V strains, respectively, on the expression of the four CYP genes was evaluated. In IVRI-IV strain, the CYP41 gene was highly overexpressed (FC 8.72) while CYP3006G8 was underexpressed with FC of 0.06. All the four genes were overexpressed in IVRI-V strain. After exposure to deltamethrin, the CYP3006G8 transcript levels were significantly upregulated at all time intervals in both resistant strains with the highest FC of 11.62 at 12 h in IVRI-IV and 13.38 at 3 h in IVRI-V. Our results suggest that the constitutive overexpression of CYP41 and deltamethrin induced upregulation of CYP3006G8 contribute to the development of pyrethroid resistance, specifically deltamethrin, in these two reference strains.
细胞色素 P450 单加氧酶介导的代谢解毒作用已被认为是对拟除虫菊酯产生抗性的机制之一，拟除虫菊酯是一类杀虫剂，包括拟除虫菊酯类杀虫剂如溴氰菊酯。在节肢动物害虫中已经鉴定出几种细胞色素 P450（CYP）基因，这些基因在暴露于作为杀螨剂使用的杀虫剂时会被上调。然而，迄今为止，关于 CYP 基因及其对杀螨剂暴露的反应在蜱中的信息有限。我们从参考敏感的 IVRI-I 株 Rhipicephalus microplus 中克隆和测序了四个 CYP 基因，即 CYP41、CYP3006G8、CYP319A1 和 CYP4W1。使用 qPCR 研究了这些基因在参考敏感的 IVRI-I、拟除虫菊酯抗性的 IVRI-IV 和多杀螨剂抗性的 IVRI-V 株中的表达模式。评估了在 2600μg/mL 和 299.7μg/mL 浓度下，单次暴露于溴氰菊酯对 IVRI-IV 和 IVRI-V 株中这四个 CYP 基因表达的影响。在 IVRI-IV 株中，CYP41 基因高度过表达（FC 8.72），而 CYP3006G8 则表达下调，FC 为 0.06。四个基因在 IVRI-V 株中均过表达。暴露于溴氰菊酯后，两个抗性株中所有四个基因在所有时间点的转录水平均显著上调，在 IVRI-IV 中最高的 FC 为 11.62，在 12 h 时，在 IVRI-V 中为 13.38，在 3 h 时。我们的结果表明，CYP41 和溴氰菊酯的组成型过表达导致 CYP3006G8 的上调可能导致这两个参考株对拟除虫菊酯，特别是溴氰菊酯的抗性发展。
