title: Increased Expression of P-Glycoprotein Is Associated With Chlorpyrifos Resistance in the German Cockroach (Blattodea: Blattellidae).
abstract: A principal method for control of the German cockroach, Blattella germanica (L.), is the broad-spectrum organophosphorus insecticide, chlorpyrifos (O,O-diethyl O-3,5,6-trichloro-2-pyridyl phosphorothioate); however, extensive and repeated application has resulted in the development of resistance to chlorpyrifos in this insect. Evidence suggests that ATP-binding cassette protein transporters, including P-glycoprotein, are involved in insecticide resistance. However, little is known of the role of P-glycoprotein in insecticide resistance in the German cockroach. Here, we developed a chlorpyrifos-resistant strain of German cockroach and investigated the relationship between P-glycoprotein and chlorpyrifos resistance using toxicity assays; inhibition studies with two P-glycoprotein inhibitors, verapamil and quinine; P-glycoprotein-ATPase activity assays; and western blotting analysis. After 23 generations of selection from susceptible strain cockroaches, we obtained animals with high resistance to chlorpyrifos. When P-glycoprotein-ATPase activity was inhibited by verapamil and quinine, we observed enhanced susceptibility to chlorpyrifos in both control and chlorpyrifos-resistant cockroaches. No significant alterations of P-glycoprotein expression or ATPase activity were observed in cockroaches acutely exposed to LD50 doses of chlorpyrifos for 24 h, while P-glycoprotein expression and ATPase activity were clearly elevated in the chlorpyrifos-resistant cockroach strain. Thus, we conclude that P-glycoprotein is associated with chlorpyrifos resistance in the German cockroach and that elevated levels of P-glycoprotein expression and ATPase activity may be an important mechanism of chlorpyrifos resistance in the German cockroach.
authors.affiliation: Laboratory of Molecular Vector Biology, Haidian Center for Disease Prevention and Control, Beijing 100094, P.R. China ( simony_hou@163.com ; 371602703@qq.com ; wangzhe7948@sina.com ; shenyanhui@263.net ; zhaoyancdc@163.com ).|Institute of Disinfection and Vector Control, Beijing Center for Disease Control and Prevention, Beijing 100013, P.R. China ( zhouxj@163.com ; qkcandy@126.com ).
authors.forename: Weiyuan
authors.initials: W
authors.lastname: Hou
authors.affiliation: Laboratory of Molecular Vector Biology, Haidian Center for Disease Prevention and Control, Beijing 100094, P.R. China (simony_hou@163.com; 371602703@qq.com; wangzhe7948@sina.com; shenyanhui@263.net; zhaoyancdc@163.com).
authors.forename: Chu
authors.initials: C
authors.lastname: Jiang
authors.affiliation: Institute of Disinfection and Vector Control, Beijing Center for Disease Control and Prevention, Beijing 100013, P.R. China (zhouxj@163.com; qkcandy@126.com).
authors.forename: Xiaojie
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Institute of Disinfection and Vector Control, Beijing Center for Disease Control and Prevention, Beijing 100013, P.R. China (zhouxj@163.com; qkcandy@126.com).
authors.forename: Kun
authors.initials: K
authors.lastname: Qian
authors.affiliation: Laboratory of Molecular Vector Biology, Haidian Center for Disease Prevention and Control, Beijing 100094, P.R. China (simony_hou@163.com; 371602703@qq.com; wangzhe7948@sina.com; shenyanhui@263.net; zhaoyancdc@163.com).
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.affiliation: Laboratory of Molecular Vector Biology, Haidian Center for Disease Prevention and Control, Beijing 100094, P.R. China (simony_hou@163.com; 371602703@qq.com; wangzhe7948@sina.com; shenyanhui@263.net; zhaoyancdc@163.com).
authors.forename: Yanhui
authors.initials: Y
authors.lastname: Shen
authors.affiliation: Laboratory of Molecular Vector Biology, Haidian Center for Disease Prevention and Control, Beijing 100094, P.R. China (simony_hou@163.com; 371602703@qq.com; wangzhe7948@sina.com; shenyanhui@263.net; zhaoyancdc@163.com).
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhao
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D020048:Blattellidae / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D004390:Chlorpyrifos / Q000494:pharmacology*; D019476:Insect Proteins / Q000235:genetics* / Q000378:metabolism; D007305:Insecticide Resistance; D007306:Insecticides / Q000494:pharmacology*
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D019476:Insect Proteins; D007306:Insecticides; D004390:Chlorpyrifos
keywords: German cockroach; P-glycoprotein; chlorpyrifos; resistance