title: Characterization of Bactrocera dorsalis serine proteases and evidence for their indirect role in insecticide tolerance.
abstract: The oriental fruit fly Bactrocera dorsalis (Hendel) causes devastating losses to agricultural crops world-wide and is considered to be an economically important pest. Little is known about the digestive enzymes such as serine proteases (SPs) in B. dorsalis, which are important both for energy supply and mitigation of fitness cost associated with insecticide tolerance. In this study, we identified five SP genes in the midgut of B. dorsalis, and the alignments of their deduced amino acid sequences revealed the presence of motifs conserved in the SP superfamily. Phylogenetic analyses with known SPs from other insect species suggested that three of them were trypsin-like proteases. Analyses of the expression profiles among the different developmental stages showed that all five genes were most abundant in larvae than in other stages. When larvae were continuously fed on diet containing 0.33 μg/g β-Cypermethrin, expression of all five genes were upregulated in the midgut but the larval development was delayed. Biochemical assays were consistent with the increased protease activity exhibited by SPs in the midgut after treatment with β-Cypermethrin. Taken together, these findings provide evidence for the hypothesis that enhanced SP activity may play an indirect role in relieving the toxicity stress of insecticide in B. dorsalis.
authors.affiliation: Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400716, China. houzi3060520@126.com.
authors.forename: Ming-Zhe
authors.initials: MZ
authors.lastname: Hou
authors.affiliation: Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400716, China. blackaet@163.com.
authors.forename: Guang-Mao
authors.initials: GM
authors.lastname: Shen
authors.affiliation: Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400716, China. dong_wei1988@yahoo.com.
authors.forename: Dong
authors.initials: D
authors.lastname: Wei
authors.affiliation: Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400716, China. Houzi15213344970@gmail.com.
authors.forename: Ya-Li
authors.initials: YL
authors.lastname: Li
authors.affiliation: Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400716, China. anwdou@gmail.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Dou
authors.affiliation: Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400716, China. wangjinjun@swu.edu.cn.
authors.forename: Jin-Jun
authors.initials: JJ
authors.lastname: Wang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D007305:Insecticide Resistance / Q000187:drug effects; D007814:Larva / Q000187:drug effects / Q000254:growth & development; D008969:Molecular Sequence Data; D010802:Phylogeny; D011722:Pyrethrins / Q000633:toxicity; D016415:Sequence Alignment; D057057:Serine Proteases / Q000737:chemistry / Q000145:classification / Q000378:metabolism*; D033621:Tephritidae / Q000201:enzymology* / Q000254:growth & development; D059467:Transcriptome
chemical_list: D011722:Pyrethrins; C017160:cypermethrin; D057057:Serine Proteases