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Xiwu Gao - One of the best experts on this subject based on the ideXlab platform.
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the overexpression and variant of cyp6g4 associated with Propoxur resistance in the housefly musca domestica l
Pest Management Science, 2021Co-Authors: Chunmei You, Chao Shan, Yi Zhang, Rui Zhao, Xiwu GaoAbstract:Background The control of housefly, Musca domestica, heavily relies on the application of insecticides. Propoxur, a carbamate, was widely used for vector control. The housefly populations with high Propoxur resistance displayed the point mutations and overexpression of the acetylcholinesterase. However, the roles of cytochrome P450 monoxygenases (P450s), as a kind of the important detoxification enzymes, remain poorly understand in the housefly resistant to Propoxur. Results P450s were implied to contribute to Propoxur resistance based on the synergism of PBO and the increase of P450 enzyme activity in the Propoxur resistance near-isogenic line (N-PRS). Five P450 (CYP6G4, CYP6A25, CYP304A1, CYP6D3, and CYP6A1) genes by RNA-seq comparison were significantly up-regulated in the N-PRS strain with >1035-fold resistance to Propoxur. A total of thirteen nonsynonymous mutations of three P450 genes (CYP6G4, CYP6D3, and CYP6D8) were found in the N-PRS strain. The amino acid substitutions of CYP6D3 and CYP6D8 were probably not resistance-associated single nucleotide polymorphisms (SNPs) because they were also found in the aabys susceptible strain. However, CYP6G4 variant in the N-PRS strain was not found in the aabys strain. The conjoint analysis of mutations and a series of genetic crosses exhibited that the housefly Propoxur resistance was strongly associated with the mutations of CYP6G4 gene. Conclusion Our results suggested that a combination of upregulated transcript levels and mutations of CYP6G4 contributed to Propoxur resistance in the housefly. This article is protected by copyright. All rights reserved.
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Propoxur resistance associated with insensitivity of acetylcholinesterase ache in the housefly musca domestica diptera muscidae
Scientific Reports, 2020Co-Authors: Chunmei You, Chao Shan, Yi Zhang, Juanjuan Xin, Xiaopeng Zeng, Xiwu GaoAbstract:Two unique housefly strains, PSS and N-PRS (near-isogenic line with the PSS), were used to clarify the mechanisms associated with Propoxur resistance in the housefly, Musca domestica. The Propoxur-selected resistant (N-PRS) strain exhibited >1035-fold resistance to Propoxur and 1.70-, 12.06-, 4.28-, 57.76-, and 57.54-fold cross-resistance to beta-cypermethrin, deltamethrin, bifenthrin, phoxim, and azamethiphos, respectively, compared to the susceptible (PSS) strain. We purified acetylcholinesterase (AChE) from the N-PRS and PSS strains using a procainamide affinity column and characterized the AChE. The sensitivity of AChE to Propoxur based on the bimolecular rate constant (Ki) was approximately 100-fold higher in the PSS strain compared to the N-PRS strain. The cDNA encoding Mdace from both the N-PRS strain and the PSS strain were cloned and sequenced using RT-PCR. The cDNA was 2073 nucleotides long and encoded a protein of 691 amino acids. A total of four single nucleotide polymorphisms (SNPs), I162M, V260L, G342A, and F407Y, were present in the region of the active site of AChE from the N-PRS strain. The transcription level and DNA copy number of Mdace were significantly higher in the resistant strain than in the susceptible strain. These results indicated that mutations combined with the up-regulation of Mdace might be essential in the housefly resistance to Propoxur.
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Inheritance of Propoxur Resistance in a Near-Isogenic Line of Musca domestica (Diptera: Muscidae)
Journal of economic entomology, 2016Co-Authors: Chao Shan, Yi Zhang, Xiwu GaoAbstract:Propoxur, a carbamate insecticide, has been used worldwide for the control of house flies (Musca domestica L.) for many decades. Resistance levels to Propoxur have been detected in field populations of house flies in many parts of the world, including China. In this study, a near-isogenic house fly line (N-PRR) resistant to Propoxur was used to determine the mode of inheritance. Bioassay results showed no significant differences in LD50 values or in the slope of log dose-probit lines between the reciprocal F1 and F1’ progenies, and the degree of dominance (D) was more than −1 and less than 0. Chi-square analysis of the responses of self-bred (F2, F2’) and backcross progenies (BC1, BC2, BC1’, and BC2’) indicated that a single gene was responsible for resistance. Propoxur resistance in the N-PRR strain of house fly was inherited as a single, major, autosomal, and incompletely recessive factor. These results should be useful to reveal the mode of inheritance and the development trend of Propoxur resistance and develop a systematic strategy for the resistance management in house flies.
Steven M Valles - One of the best experts on this subject based on the ideXlab platform.
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effects of the synergists piperonyl butoxide and s s s tributyl phosphorotrithioate on Propoxur pharmacokinetics in blattella germanica blattodea blattellidae
Journal of Economic Entomology, 2001Co-Authors: Hussein Sanchezarroyo, Philip G Koehler, Steven M VallesAbstract:Effects of the synergists piperonyl butoxide (PBO) and S,S,S-tributyl phosphorotrithioate (DEF) on Propoxur pharmacokinetics were examined in the German cockroach, Blattella germanica (L.). Treatment of adult male German cockroaches with the cytochrome P450 monooxygenase inhibitor, PBO, or the esterase inhibitor, DEF, increased Propoxur toxicity by 2- and 6.8-fold, respectively, implicating hydrolysis as a major detoxification route of Propoxur in the German cockroach. However, significant hydrolytic metabolism could not be demonstrated conclusively in vitro resulting in a conflict between in situ bioassay data and in vitro metabolic studies. In vitro Propoxur metabolism with NADPH-fortified microsomes produced at least nine metabolites. Formation of metabolites was NADPH-dependent; no quantifiable metabolism was detected with cytosolic fractions. However, microsomal fractions lacking an NADPH source did produce a low, but detectable, quantity of metabolites (1.6 pmol). PBO inhibited NADPH-dependent Propoxur metabolism in a dose-dependent fashion, implicating cytochrome P450 monooxygenases as the enzyme system responsible for the metabolism. Interestingly, DEF also inhibited the NADPH-dependent metabolism of Propoxur, albeit to a lower extent. Treatment with PBO or DEF also caused a significant reduction in the cuticular penetration rate of Propoxur. The data demonstrate that unanticipated effects are possible with synergists and that caution must be exercised when interpreting synergist results.
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effects of the synergists piperonyl butoxide and s s s tributyl phosphorotrithioate on Propoxur pharmacokinetics in blattella germanica blattodea blattellidae
Journal of Economic Entomology, 2001Co-Authors: Hussein Sanchezarroyo, Philip G Koehler, Steven M VallesAbstract:Effects of the synergists piperonyl butoxide (PBO) and S,S,S-tributyl phosphorotrithioate (DEF) on Propoxur pharmacokinetics were examined in the German cockroach, Blattella germanica (L.). Treatment of adult male German cockroaches with the cytochrome P450 monooxygenase inhibitor, PBO, or the esterase inhibitor, DEF, increased Propoxur toxicity by 2- and 6.8-fold, respectively, implicating hydrolysis as a major detoxification route of Propoxur in the German cockroach. However, significant hydrolytic metabolism could not be demonstrated conclusively in vitro resulting in a conflict between in situ bioassay data and in vitro metabolic studies. In vitro Propoxur metabolism with NADPH-fortified microsomes produced at least nine metabolites. Formation of metabolites was NADPH-dependent; no quantifiable metabolism was detected with cytosolic fractions. However, microsomal fractions lacking an NADPH source did produce a low, but detectable, quantity of metabolites (1.6 pmol). PBO inhibited NADPH-dependent Propoxur metabolism in a dose-dependent fashion, implicating cytochrome P450 monooxygenases as the enzyme system responsible for the metabolism. Interestingly, DEF also inhibited the NADPH-dependent metabolism of Propoxur, albeit to a lower extent. Treatment with PBO or DEF also caused a significant reduction in the cuticular penetration rate of Propoxur. The data demonstrate that unanticipated effects are possible with synergists and that caution must be exercised when interpreting synergist results.
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biochemical mechanisms responsible for stage dependent Propoxur tolerance in the german cockroach
Pesticide Biochemistry and Physiology, 1996Co-Authors: Steven M Valles, Philip G KoehlerAbstract:Abstract Final instar nymphs and adult males of the Village Green strain of German cockroach were investigated to determine the biochemical mechanisms responsible for conferring stage-dependent Propoxur tolerance. Propoxur susceptibility was dependent upon age within the final instar. Final instar nymphs (1 day old) were as susceptible to topically applied Propoxur as adult males (7 to 14 days old) while 7- and 12-day-old nymphs were up to 16-fold more tolerant. Piperonyl butoxide, a cytochrome P450 monooxygenase inhibitor, almost completely eliminated the tolerance of Propoxur in male and female nymphs compared with adult males. The rate of in vitro microsomal oxidation of Propoxur was three times higher in male and female final instars than in adult males. Nymphs had significantly higher cytochrome P450 content and methoxyresorufin O -demethylase and ethoxyresorufin O -deethylase activities than adult males. Similar k i (bimolecular rate constant) values for Propoxur in nymphs and adult males indicated that acetylcholinesterase insensitivity did not contribute to the enhanced nymphal tolerance. Cuticular penetration studies using [ 14 C]Propoxur revealed that there was no marked difference in the rate of penetration of Propoxur in nymphs and adults. However, compared with adult males, less radioactivity was observed in nymph internal extracts and more was observed in nymphal excreta. The results indicated that nymphal tolerance toward Propoxur was largely due to enhanced microsomal oxidation.
Philip G Koehler - One of the best experts on this subject based on the ideXlab platform.
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effects of the synergists piperonyl butoxide and s s s tributyl phosphorotrithioate on Propoxur pharmacokinetics in blattella germanica blattodea blattellidae
Journal of Economic Entomology, 2001Co-Authors: Hussein Sanchezarroyo, Philip G Koehler, Steven M VallesAbstract:Effects of the synergists piperonyl butoxide (PBO) and S,S,S-tributyl phosphorotrithioate (DEF) on Propoxur pharmacokinetics were examined in the German cockroach, Blattella germanica (L.). Treatment of adult male German cockroaches with the cytochrome P450 monooxygenase inhibitor, PBO, or the esterase inhibitor, DEF, increased Propoxur toxicity by 2- and 6.8-fold, respectively, implicating hydrolysis as a major detoxification route of Propoxur in the German cockroach. However, significant hydrolytic metabolism could not be demonstrated conclusively in vitro resulting in a conflict between in situ bioassay data and in vitro metabolic studies. In vitro Propoxur metabolism with NADPH-fortified microsomes produced at least nine metabolites. Formation of metabolites was NADPH-dependent; no quantifiable metabolism was detected with cytosolic fractions. However, microsomal fractions lacking an NADPH source did produce a low, but detectable, quantity of metabolites (1.6 pmol). PBO inhibited NADPH-dependent Propoxur metabolism in a dose-dependent fashion, implicating cytochrome P450 monooxygenases as the enzyme system responsible for the metabolism. Interestingly, DEF also inhibited the NADPH-dependent metabolism of Propoxur, albeit to a lower extent. Treatment with PBO or DEF also caused a significant reduction in the cuticular penetration rate of Propoxur. The data demonstrate that unanticipated effects are possible with synergists and that caution must be exercised when interpreting synergist results.
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effects of the synergists piperonyl butoxide and s s s tributyl phosphorotrithioate on Propoxur pharmacokinetics in blattella germanica blattodea blattellidae
Journal of Economic Entomology, 2001Co-Authors: Hussein Sanchezarroyo, Philip G Koehler, Steven M VallesAbstract:Effects of the synergists piperonyl butoxide (PBO) and S,S,S-tributyl phosphorotrithioate (DEF) on Propoxur pharmacokinetics were examined in the German cockroach, Blattella germanica (L.). Treatment of adult male German cockroaches with the cytochrome P450 monooxygenase inhibitor, PBO, or the esterase inhibitor, DEF, increased Propoxur toxicity by 2- and 6.8-fold, respectively, implicating hydrolysis as a major detoxification route of Propoxur in the German cockroach. However, significant hydrolytic metabolism could not be demonstrated conclusively in vitro resulting in a conflict between in situ bioassay data and in vitro metabolic studies. In vitro Propoxur metabolism with NADPH-fortified microsomes produced at least nine metabolites. Formation of metabolites was NADPH-dependent; no quantifiable metabolism was detected with cytosolic fractions. However, microsomal fractions lacking an NADPH source did produce a low, but detectable, quantity of metabolites (1.6 pmol). PBO inhibited NADPH-dependent Propoxur metabolism in a dose-dependent fashion, implicating cytochrome P450 monooxygenases as the enzyme system responsible for the metabolism. Interestingly, DEF also inhibited the NADPH-dependent metabolism of Propoxur, albeit to a lower extent. Treatment with PBO or DEF also caused a significant reduction in the cuticular penetration rate of Propoxur. The data demonstrate that unanticipated effects are possible with synergists and that caution must be exercised when interpreting synergist results.
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biochemical mechanisms responsible for stage dependent Propoxur tolerance in the german cockroach
Pesticide Biochemistry and Physiology, 1996Co-Authors: Steven M Valles, Philip G KoehlerAbstract:Abstract Final instar nymphs and adult males of the Village Green strain of German cockroach were investigated to determine the biochemical mechanisms responsible for conferring stage-dependent Propoxur tolerance. Propoxur susceptibility was dependent upon age within the final instar. Final instar nymphs (1 day old) were as susceptible to topically applied Propoxur as adult males (7 to 14 days old) while 7- and 12-day-old nymphs were up to 16-fold more tolerant. Piperonyl butoxide, a cytochrome P450 monooxygenase inhibitor, almost completely eliminated the tolerance of Propoxur in male and female nymphs compared with adult males. The rate of in vitro microsomal oxidation of Propoxur was three times higher in male and female final instars than in adult males. Nymphs had significantly higher cytochrome P450 content and methoxyresorufin O -demethylase and ethoxyresorufin O -deethylase activities than adult males. Similar k i (bimolecular rate constant) values for Propoxur in nymphs and adult males indicated that acetylcholinesterase insensitivity did not contribute to the enhanced nymphal tolerance. Cuticular penetration studies using [ 14 C]Propoxur revealed that there was no marked difference in the rate of penetration of Propoxur in nymphs and adults. However, compared with adult males, less radioactivity was observed in nymph internal extracts and more was observed in nymphal excreta. The results indicated that nymphal tolerance toward Propoxur was largely due to enhanced microsomal oxidation.
Chunmei You - One of the best experts on this subject based on the ideXlab platform.
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the overexpression and variant of cyp6g4 associated with Propoxur resistance in the housefly musca domestica l
Pest Management Science, 2021Co-Authors: Chunmei You, Chao Shan, Yi Zhang, Rui Zhao, Xiwu GaoAbstract:Background The control of housefly, Musca domestica, heavily relies on the application of insecticides. Propoxur, a carbamate, was widely used for vector control. The housefly populations with high Propoxur resistance displayed the point mutations and overexpression of the acetylcholinesterase. However, the roles of cytochrome P450 monoxygenases (P450s), as a kind of the important detoxification enzymes, remain poorly understand in the housefly resistant to Propoxur. Results P450s were implied to contribute to Propoxur resistance based on the synergism of PBO and the increase of P450 enzyme activity in the Propoxur resistance near-isogenic line (N-PRS). Five P450 (CYP6G4, CYP6A25, CYP304A1, CYP6D3, and CYP6A1) genes by RNA-seq comparison were significantly up-regulated in the N-PRS strain with >1035-fold resistance to Propoxur. A total of thirteen nonsynonymous mutations of three P450 genes (CYP6G4, CYP6D3, and CYP6D8) were found in the N-PRS strain. The amino acid substitutions of CYP6D3 and CYP6D8 were probably not resistance-associated single nucleotide polymorphisms (SNPs) because they were also found in the aabys susceptible strain. However, CYP6G4 variant in the N-PRS strain was not found in the aabys strain. The conjoint analysis of mutations and a series of genetic crosses exhibited that the housefly Propoxur resistance was strongly associated with the mutations of CYP6G4 gene. Conclusion Our results suggested that a combination of upregulated transcript levels and mutations of CYP6G4 contributed to Propoxur resistance in the housefly. This article is protected by copyright. All rights reserved.
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Propoxur resistance associated with insensitivity of acetylcholinesterase ache in the housefly musca domestica diptera muscidae
Scientific Reports, 2020Co-Authors: Chunmei You, Chao Shan, Yi Zhang, Juanjuan Xin, Xiaopeng Zeng, Xiwu GaoAbstract:Two unique housefly strains, PSS and N-PRS (near-isogenic line with the PSS), were used to clarify the mechanisms associated with Propoxur resistance in the housefly, Musca domestica. The Propoxur-selected resistant (N-PRS) strain exhibited >1035-fold resistance to Propoxur and 1.70-, 12.06-, 4.28-, 57.76-, and 57.54-fold cross-resistance to beta-cypermethrin, deltamethrin, bifenthrin, phoxim, and azamethiphos, respectively, compared to the susceptible (PSS) strain. We purified acetylcholinesterase (AChE) from the N-PRS and PSS strains using a procainamide affinity column and characterized the AChE. The sensitivity of AChE to Propoxur based on the bimolecular rate constant (Ki) was approximately 100-fold higher in the PSS strain compared to the N-PRS strain. The cDNA encoding Mdace from both the N-PRS strain and the PSS strain were cloned and sequenced using RT-PCR. The cDNA was 2073 nucleotides long and encoded a protein of 691 amino acids. A total of four single nucleotide polymorphisms (SNPs), I162M, V260L, G342A, and F407Y, were present in the region of the active site of AChE from the N-PRS strain. The transcription level and DNA copy number of Mdace were significantly higher in the resistant strain than in the susceptible strain. These results indicated that mutations combined with the up-regulation of Mdace might be essential in the housefly resistance to Propoxur.
Chao Shan - One of the best experts on this subject based on the ideXlab platform.
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the overexpression and variant of cyp6g4 associated with Propoxur resistance in the housefly musca domestica l
Pest Management Science, 2021Co-Authors: Chunmei You, Chao Shan, Yi Zhang, Rui Zhao, Xiwu GaoAbstract:Background The control of housefly, Musca domestica, heavily relies on the application of insecticides. Propoxur, a carbamate, was widely used for vector control. The housefly populations with high Propoxur resistance displayed the point mutations and overexpression of the acetylcholinesterase. However, the roles of cytochrome P450 monoxygenases (P450s), as a kind of the important detoxification enzymes, remain poorly understand in the housefly resistant to Propoxur. Results P450s were implied to contribute to Propoxur resistance based on the synergism of PBO and the increase of P450 enzyme activity in the Propoxur resistance near-isogenic line (N-PRS). Five P450 (CYP6G4, CYP6A25, CYP304A1, CYP6D3, and CYP6A1) genes by RNA-seq comparison were significantly up-regulated in the N-PRS strain with >1035-fold resistance to Propoxur. A total of thirteen nonsynonymous mutations of three P450 genes (CYP6G4, CYP6D3, and CYP6D8) were found in the N-PRS strain. The amino acid substitutions of CYP6D3 and CYP6D8 were probably not resistance-associated single nucleotide polymorphisms (SNPs) because they were also found in the aabys susceptible strain. However, CYP6G4 variant in the N-PRS strain was not found in the aabys strain. The conjoint analysis of mutations and a series of genetic crosses exhibited that the housefly Propoxur resistance was strongly associated with the mutations of CYP6G4 gene. Conclusion Our results suggested that a combination of upregulated transcript levels and mutations of CYP6G4 contributed to Propoxur resistance in the housefly. This article is protected by copyright. All rights reserved.
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Propoxur resistance associated with insensitivity of acetylcholinesterase ache in the housefly musca domestica diptera muscidae
Scientific Reports, 2020Co-Authors: Chunmei You, Chao Shan, Yi Zhang, Juanjuan Xin, Xiaopeng Zeng, Xiwu GaoAbstract:Two unique housefly strains, PSS and N-PRS (near-isogenic line with the PSS), were used to clarify the mechanisms associated with Propoxur resistance in the housefly, Musca domestica. The Propoxur-selected resistant (N-PRS) strain exhibited >1035-fold resistance to Propoxur and 1.70-, 12.06-, 4.28-, 57.76-, and 57.54-fold cross-resistance to beta-cypermethrin, deltamethrin, bifenthrin, phoxim, and azamethiphos, respectively, compared to the susceptible (PSS) strain. We purified acetylcholinesterase (AChE) from the N-PRS and PSS strains using a procainamide affinity column and characterized the AChE. The sensitivity of AChE to Propoxur based on the bimolecular rate constant (Ki) was approximately 100-fold higher in the PSS strain compared to the N-PRS strain. The cDNA encoding Mdace from both the N-PRS strain and the PSS strain were cloned and sequenced using RT-PCR. The cDNA was 2073 nucleotides long and encoded a protein of 691 amino acids. A total of four single nucleotide polymorphisms (SNPs), I162M, V260L, G342A, and F407Y, were present in the region of the active site of AChE from the N-PRS strain. The transcription level and DNA copy number of Mdace were significantly higher in the resistant strain than in the susceptible strain. These results indicated that mutations combined with the up-regulation of Mdace might be essential in the housefly resistance to Propoxur.
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Inheritance of Propoxur Resistance in a Near-Isogenic Line of Musca domestica (Diptera: Muscidae)
Journal of economic entomology, 2016Co-Authors: Chao Shan, Yi Zhang, Xiwu GaoAbstract:Propoxur, a carbamate insecticide, has been used worldwide for the control of house flies (Musca domestica L.) for many decades. Resistance levels to Propoxur have been detected in field populations of house flies in many parts of the world, including China. In this study, a near-isogenic house fly line (N-PRR) resistant to Propoxur was used to determine the mode of inheritance. Bioassay results showed no significant differences in LD50 values or in the slope of log dose-probit lines between the reciprocal F1 and F1’ progenies, and the degree of dominance (D) was more than −1 and less than 0. Chi-square analysis of the responses of self-bred (F2, F2’) and backcross progenies (BC1, BC2, BC1’, and BC2’) indicated that a single gene was responsible for resistance. Propoxur resistance in the N-PRR strain of house fly was inherited as a single, major, autosomal, and incompletely recessive factor. These results should be useful to reveal the mode of inheritance and the development trend of Propoxur resistance and develop a systematic strategy for the resistance management in house flies.
