Progress 10/01/97 to 09/30/03
Outputs Spinosad is a new and highly promising insecticide with efficacy against a wide range of insects, including house flies. Selection of the field collected house flies produced a highly spinosad resistant (greater than 150-fold) strain of house fly following 10 generations of selection. Spinosad resistance was a recessive trait linked to autosome 1 which could not be overcome with the insecticide synergists piperonyl butoxide, S,S,S, tributylphosphorotrithioate nor diethyl maleate. Selection for resistance to spinosad did not result in cross-resistance to other insecticides. These results suggest spinosad resistance in the house fly is due to a unique resistance mechanism.
Impacts Spinosad resistance was readily selectable from filed populations suggesting the genes for resistance are relatively frequent and spinosad must be used carefully or resistance will cause this promising insecticide to become ineffective.
Publications
- Scott, J. G. and Zhang, L. 2003. The house fly aliesterase gene (MdalphaE7) is not associated with insecticide resistance or P450 expression in three strains of house fly. Insect Biochem. Molec. Biol. 33: 139-144.
- Shono, T. and Scott, J. G. 2003. Spinosad resistance in the house fly, Musca domestica, is due to a recessive factor on autosome 1. Pestic. Biochem. Physiol. 75: 1-7.
- Brown, D., Zhang, L., Wen, Z. and Scott, J. G. 2003. Induction of P450 monooxygenases in the German cockroach Blattella Germanica L. Arch. Insect Biochem. Physiol. 53: 119-124.
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Progress 01/01/02 to 12/31/02
Outputs CYP6D1 is the cytochrome P450 responsible for pyrethroid resistance in the LPR strain of house fly which was originally collected from New York, and was recently implicated as a mechanism of resistance in house flies from Georgia. We sequenced CYP6D1 from the NG98 strain of house fly from Georgia and found that the CYP6D1 allele in this strain is identical to that found in the LPR strain (CYP6D1v1). This is in contrast to the other five alleles of CYP6D1 from pyrethroid susceptible strains which were all unique (i.e. different from all other strains). These results indicate that CYP6D1-mediated resistance may have evolved once and then spread between these two states. This is unexpected as house flies are not documented to disperse over long distances. The finding of identical alleles in the pyrethroid resistant NG98 and LPR strains supports the hypothesis that the different CYP6D1 protein in resistant strains contributes to their resistance.
Impacts One important aspect for the development of effective resistance management tactics is to understand the geographic area over which a strategy must be implemented. Our results suggest mixing of populations from places as distant as New York and Georgia. This suggests that resistance management would have to be undertaken over an enormous area in order to have the greatest chance of success.
Publications
- Scott, J. G. and Kasai, S. 2002. Monooxygenase-Mediated Insecticide Resistance: Regulation of CYP6D1 Expression. In Agrochemical Resistance Extent, Mechanism and Detection, J. M. Clark and I. Yamaguchi, eds. ACS, Washington, DC, pp. 24-41.
- Seifert, J. and Scott, J. G. 2002. The CYP6D1v1 allele is associated with insecticide resistance. Pestic. Biochem. Physiol. 72: 40-44.
- Shono, T., Kasai, S., Kamiya, E., Kono, Y. and Scott, J. G. 2002. Genetics and mechanisms of permethrin resistance in the YPER strain of house fly. Pestic. Biochem. Physiol. 73: 27-36.
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Progress 01/01/01 to 12/31/01
Outputs The P450 monooxygenases of insects are important in the metabolism of numerous endogenous and exogenous compounds. However, identity of the P450 isoform(s) involved in these reactions is rarely known. A critical first step in the identification of important P450s is the cloning and sequencing of their genes. Toward this goal we report the genomic sequence of a new cytochrome P450, termed CYP6D3, from the house fly, Musca domestica. CYP6D3 is part of a P450 gene cluster located on chromosome 1 and is located upstream of a related gene, CYP6D1. The similar genetic structures of CYP6D3 and CYP6D1 (5 exons and 4 introns of similar length) suggest one of these genes may have been the result of a duplication event. The CYP6D3 deduced amino acid sequence indicates a protein with 518 amino acids and a molecular weight of 59.3 kDa. The CYP6D3 protein is most similar to house fly CYP6D1 (78 %) and CYP6D2 (56%) from Drosophila melanogaster. The deduced amino acid sequences of
CYP6D3 and CYP6D1 are identical at the Helix I and heme binding regions.
Impacts CYP6D1 is responsible for monooxygenase mediated pyrethroid resistance in house flies. The identification of an adjacent P450 gene (CYP6D3) offers new evidence to support the role of the CYP6D1v1 allele in resistance. These results will help to identify possible regulatory regions that are responsible for resistance and lead to the development of sensitive resistance monitoring methods.
Publications
- Wen, Z. and Scott, J. G. 2001. Cytochrome P450 CYP6L1 is specifically expressed in the reproductive tissues of adult male German cockroaches, Blattella germanica (L.). Insect Biochem. Molec. Biol. 31: 179-187.
- Scott, J. G. 2001. Cytochrome P450 monooxygenases and insecticide resistance: lessons from CYP6D1. In Biochemical Sites of Insecticide Action and Resistance, I. Ishaaya, ed. Springer-Verlag, New York, pp 255-267.
- Wen, Z. and Scott, J. G. 2001. Cloning of two novel P450 cDNAs from German cockroaches, Blattella germanica (L.): CYP6K1 and CYP6J1. Insect Molec. Biol. 10: 131-137.
- Kasai, S. and Scott, J. G. 2001. Cytochrome P450s CYP6D3 and CYP6D1 are part of a P450 gene cluster on autosome 1 in house fly. Insect Molec. Biol. 10: 191-196.
- Kasai, S. and Scott, J. G. 2001. A house fly gene homologous to the zinc finger proto-oncogene Gfi-1. Biochem. Biophys. Res. Comm. 283: 644-647.
- Kaufman, P. E., Scott, J. G. and Rutz, D. A. 2001. Monitoring insecticide resistance in house flies (Diptera:Muscidae) from New York dairies. Pest Manag. Sci. 57: 514-521.
- Wen, Z., Horak, C. E. and Scott, J. G. 2001. CYP9E2, CYP4C21 and related pseudogenes from German cockroaches, Blattella germanica: implications for molecular evolution, expression studies and nomenclature of P450s. Gene 272: 257-266.
- Scott, J. G. and Wen, Z. 2001. Cytochromes P450 of insects: the tip of the iceberg. Pest Management Sci. 57: 958-967.
- Kasai, S. and Scott, J. G. 2001. Expression and regulation of CYP6D3 in house fly, Musca domestica (L). Insect Biochem. Molec. Biol. 32: 1-8.
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Progress 01/01/00 to 12/31/00
Outputs The frequency of resistance of eight strains of house flies, Musca domestica L., collected from caged-layer poultry facilities across New York state, to nine insecticides (dimethoate, tetrachlorvinphos, permethrin, cyfluthrin, pyrethrins, methomyl, fipronil, spinosad and cyromazine) was measured relative to a laboratory?susceptible strain. Percent survival was evaluated at five diagnostic concentrations: susceptible strain LC99, 3 X LC99, 10 X LC99, 30 X LC99 and 100 X LC99. The highest levels of resistance were noted for tetrachlorvinphos, permethrin and cyfluthrin. There was substantial variation in the levels of resistance to the different insecticides from one facility to another, independent of their geographical location. There was very little cross-resistance detected in these populations to either fipronil or spinosad. Overall, there was a good correlation between insecticide use histories and the levels of resistance.
Impacts The apparent isolation of fly populations within poultry facilities suggests that there are good opportunities for the implementation of successful resistance management strategies at these facilities. Implementation of an effective resistance management program would be a financial benefit for poultry producers in the northern United States
Publications
- Scott, J. G., Alefantis, T. G., Kaufman, P.E. and Rutz, D. A. 2000. Insecticide resistance in house flies from caged-layer poultry facilities. Pest Management Sci. 56: 147-153.
- Scott J. G., Foroozesh, M., Hopkins, N. E., Alefantis, T. G. and Alworth, W. L. 2000. Inhibition of cytochrome P450 6D1 by alkynylarenes, methylenedioxyarenes and other substituted aromatics, Pestic. Biochem. Physiol. 67: 63-71.
- Kasai, S. and Scott, J. G. 2000. Over-expression of cytochrome P450 CYP6D1 in pyrethroid resistant strains of house fly from North America. Pestic. Biochem. Physiol. 68: 34-41.
- Korytko, P. K., MacIntyre, R. J. and Scott, J. G. 2000. Expression and activity of a house-fly cytochrome P450, CYP6D1, in Drosophila melanogaster. Insect Molec. Biol. 9: 441-449.
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Progress 01/01/99 to 12/31/99
Outputs Fipronil is a new insecticide which exerts its toxic action by interacting with the insect GABA gated chloride channel. Previous studies have shown that cyclodiene resistant insects have low to moderate levels of cross-resistance to fipronil, while other resistant strains are usually susceptible. In contrast, we recently found a strain (LPR) of house fly (Musca domestica) with 15-fold cross-resistance to fipronil that was not associated with cyclodiene resistance. Fipronil cross-resistance in LPR was inherited as an intermediately dominant, autosomal, multigenic trait. [14C]fipronil was observed to penetrate into LPR flies more slowly than into susceptible flies. S, S, S-tributylphosphorotrithioate and diethyl maleate pretreatment did not reduce the level of fipronil cross-resistance, while piperonyl butoxide resulted in a slight decrease. These results indicate that decreased penetration and monooxygenase-mediated detoxification may be mechanisms contributing to
fipronil cross-resistance in the LPR strain.
Impacts (N/A)
Publications
- Scott, J. G., Liu, N., Wen, Z., Smith, F. F., Kasai, S. and Horak, C. E. 1999. House fly cytochrome P450 CYP6D1: 5 flanking sequences and comparison of alleles. Gene 226: 347-353.
- Wen, Z. and Scott, J. G. 1999. Genetics and mechanisms of fipronil cross-resistance in the LPR strain of house fly, Musca domestica. Pestic. Sci. 55: 988-992.
- Waldstein, D. E., Reissig, W. H., Scott, J. G. and Straub, R. W. 1999. Susceptibility of obliquebanded leafroller (Lepidoptera: Tortricidae) populations from commercial apple orchards and an unsprayed habitat in New York to tebufenozide. J. Econ. Entomol. 92: 1251-1255.
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Progress 01/01/98 to 12/31/98
Outputs Insecticide resistance is a major problem that continues to plague efforts to control pests of animals and crops. An important mechanism by which insects become resistant to insecticides is via increased detoxification mediated by the cytochrome P450 microsomal monooxygenases (monooxygenases). One of the fundamental gaps in our knowledge about this resistance mechanism is an understanding of how insects express high levels of the specific cytochrome P450(s) responsible for resistance. One such P450, CYP6D1, causes resistance to pyrethroid insecticides in the house fly and is expressed at 9-fold higher levels (mRNA and protein) in the Learn Pyrethroid Resistant (LPR) strain (compared to susceptible strains). The relative stability of CYP6D1 mRNA in resistant and susceptible strains was measured following inhibition of transcription with actinomycin D. The same time course of decrease in CYP6D1 mRNA abundance was detected in both strains indicating that the high level
of expression of CYP6D1 in LPR is not due to increased stability of the mRNA. The comparative rates of transcription of CYP6D1 were measured using an in vitro run-on transcription assay. The relative amount of CYP6D1 transcript produced in this assay was 10-fold greater in the LPR strain compared to the susceptible strain. This demonstrates that increased transcription of CYP6D1 is an underlying cause of monooxygenase-mediated insecticide resistance.
Impacts (N/A)
Publications
- Liu, N. and Scott, J. G. 1998. Increased transcription of CYP6D1 causes cytochrome P450-mediated insecticide resistance in house fly. Insect Biochem. Molec. Biol. 28: 531-535. Scott, J. G. 1998. Toxicity of spinosad to susceptible and resistant strains of house flies, Musca domestica. Pestic. Sci. 54: 131-133. Scott, J. G., Liu, N. and Wen, Z. 1998. Insect cytochromes P450: diversity, insecticide resistance and tolerance to plant toxins. Comp. Biochem. Physiol. 121C: 147-155. Scott, J. G. 1998. a-Tocopherol antagonizes the toxicity of the pyrethroid insecticide permethrin in susceptible and kdr-resistant insects. J. Pestic. Sci. 23: 399-401.
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Progress 01/01/97 to 12/31/97
Outputs CYP6D1 is a house fly cytochrome P450 known to metabolize neurotoxic pyrethroid insecticides. To determine if the nervous system was capable of metabolizing pyrethroids, we examined CYP6D1 mediated in vitro metabolism in thoracic ganglia from pyrethroid resistant (LPR) and susceptible (CS) strains of house fly. SDS-PAGE/immuno-blotting revealed that CYP6D1 was expressed in all tagmata and in thoracic ganglia of both strains, but in all cases the levels of CYP6D1 were higher in the LPR strain. Using a CYP6D1 specific antiserum, CYP6D1 was shown to be the major, and possibly the only, P450 isozyme involved in cypermethrin metabolism in thoracic ganglia homogenates. Additionally, thoracic ganglia homogenates from LPR house flies metabolize more cypermethrin than preparations from susceptible flies. This metabolism was inhibited by piperonyl butoxide and a CYP6D1 specific antibody. Our results indicate that thoracic ganglia of LPR house flies are protected from the
neurotoxin cypermethrin by virtue of the higher levels of CYP6D1 compared to the susceptible house flies. This P450 mediated detoxification of an insecticide at the level of the target tissue helps to explain the high levels of resistance to pyrethroids in the LPR strain.
Impacts (N/A)
Publications
- Scott, J. G. and Wen, Z. 1997. Toxicity of fipronil to susceptible and resistant strains of German cockroaches (Dictyoptera: Blattellidae) and house flies (Diptera: Muscidae). J. Econ. Entomol.
- Liu, N. and Scott, J. G. 1997. Phenobarbital induction of CYP6D1 is due to a trans acting factor on autosome 2 in house flies, Musca domestica. Insect Molec. Biol. 6: 77-81.
- Liu, N. and Scott, J. G. 1997. Inheritance of CYP6D1-mediated pyrethroid resistance in house fly (Diptera: Muscidae). J. Econ.
- Korytko, P. K. and Scott, J. G. 1998. CYP6D1 protects thoracic ganglia of house flies from the neurotoxic insecticide cypermethrin. Arch. Insect Biochem. Physiol. 37: 57-63.
- Wen, Z. and Scott, J. G. 1997. Cross-Resistance to imidacloprid in strains of German cockroach (Blattella germanica) and house fly (Musca domestica). Pestic. Sci. 49: 367-371.
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Progress 01/01/96 to 12/30/96
Outputs CYP6D1 is a cytochrome P450 responsible for the metabolism of insecticides and other xenobiotics in the house fly (Musca domestica). Using a CYP6D1-specific monooxygenase activity and a non-CYP6D1-specific monooxygenase activity 21 compounds were evaluated as inhibitors of CYP6D1 in house fly microsomes. CYP6D1 was strongly inhibited by xanthotoxin, chlorpyrifos, -napthoflavone, piperonyl butoxide and 5-methoxypsoralen. The highest selectivity for inhibition of CYP6D1 was seen for 5-methoxypsoralen, xanthotoxin, -napthoflavone, chlorpyrifos oxon, isosafrole and psoralen. The results clearly indicate that identification of isoform selective inhibitors of P450s within an insect, and across species, is possible. In addition, psoralen and 5-methoxypsoralen stimulated ethoxycoumarin O-deethylation suggesting that these compounds were substrates for monooxygenases in house fly microsomes. Isosafrole was shown to be a potent synergist of pyrethroid insecticides in adult
house flies.
Impacts (N/A)
Publications
- Zhang, M. and Scott, J. G. 1996. Purification and characterization of cytochrome b5 reductase from the house fly, Musca domestica. Comp. Biochem. Physiol. 113B: 175-183.
- Moss, J. I. and Scott, J. G. 1996. Tetrotodotoxin protects German cockroaches (Dictyoptera: Blattellidae) from type I pyrethroid and carbamate insecticide poisoning. J. Econ Entomol. 89: 51-55.
- Scott, J. G. and Roberts, M. A. 1996. Phenobarbital and 3- methylcholanthrene inducible cytochromes P450 are not responsible for metabolism of deltamethrin in rat liver microsomes. J. Pestic. Sci. 21: 57-60.
- Scott, J. G. 1996. Preparation of microsomes from insects and purification of CYP6D1 from house flies. In Methods in Enzymology, Vol. 272, Cytochrome P450 Part B. E. F. Johnson and M. R. Waterman, eds. Academic Press, pp 287-292.
- Zhang, M. and Scott, J. G. 1996. Cytochrome b5 is essential for cytochrome P450 6D1-mediated cypermethrin resistance in LPR house flies. Pestic. Biochem. Physiol. 55: 150-156.
- Scott, J. G. 1996. Inhibitors of CYP6D1 in house fly microsomes. Insect Biochem. Molec. Biol. 26: 645-649.
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Progress 01/01/95 to 12/30/95
Outputs CYP6D1 is a cytochrome P450 responsible for the metabolism of insecticides and other xenobiotics in the house fly (Musca domestica). Using a CYP6D1-specific monooxygenase activity and a non-CYP6D1-specific monooxygenase activity 21 compounds were evaluated as inhibitors of CYP6D1 in house fly Microsomes. CYP6D1 was strongly inhibited by xanthotoxin, chlorpyrifos, -napthoflavone, piperonyl butoxide and 5-methoxypsoralen. The highest selectivity for inhibition of CYP6D1 was seen for 5-methoxypsoralen, xanthotoxin, -napthoflavone, chlorpyrifos oxon, isosafrole and psoralen. The results clearly indicate that identification of isoform selective inhibitors of P450s within an insect, and across species, is possible. In addition, psoralen and 5-methoxypsoralen stimulated ethoxycoumarin O-deethylation suggesting that these compounds were substrates for monooxygenases in house fly Microsomes. Isosafrole was shown to be a potent synergist of pyrethroid insecticides in adult
house flies.
Impacts (N/A)
Publications
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Progress 01/01/94 to 12/30/94
Outputs The microsomal cytochrome P450-dependent monooxygenases (hereafter called "monooxygenases") constitute an extremely important metabolic system in which activity can be induced upon exposure to certain compounds. To better understand the regulation of cytochrome P450lpr in the house fly (Musca domestica), the effects of 21 potential monooxygenase inducers were examined for their ability to induce total cytochromes P450 and cytochrome P450lpr levels. Six compounds caused induction of total cytochrome P450s per mg protein in susceptible (CS) house flies: ethanol (1.6-fold), phenobarbital in the food or water (1.5-fold), naphthalene (1.3-fold), DDT (1.3-fold), xanthotoxin (1.4-fold) and -pinene (1.2-fold). Six compounds were found to be inducers of cytochrome P450lpr: PBO in food (1.9-fold), phenobarbital in food (1.4-fold) and water (3.4-fold), clofibrate (1.3-fold), xanthotoxin (1.3-fold), methohexital (1.3-fold) and isosafrole (1.3-fold). Northern blots of phenobarbital
treated CS flies indicated that there was a 4.2-fold increase in the CYP6D1 mRNA levels over the untreated flies. In the multiresistant LPR strain there was no apparent induction of CYP6D1 mRNA by phenobarbital. Following phenobarbital induction the levels of CYP6D1 mRNA in the CS strain are only about half of the level in the LPR strain.
Impacts (N/A)
Publications
- WHEELOCK, G.D. AND SCOTT, J.G. 1994. Detection of cytochrome b5 from the house fly Musca domestica: comparison of immunological and spectrophotometric methods, Comp. Biochem. Physiol. 108B: 209-214.
- DONG, K. AND SCOTT, J. G. 1994. Linkage of kdr-type resistance and the para-homologous sodium channel in German cockroaches (Blattella germanica), Insect Biochem. Molec. Biol. 24: 647-654.
- ZHANG, M. AND SCOTT, J. G. 1994. Simple synthesis of pyrethroid metabolites. J. Agric. Food Chem. 42: 1779-1782.
- ZHANG, M. AND SCOTT, J. G. 1994. Cytochrome b5 involvement in cytochrome P450 monooxygenase activities in house fly microsomes. Arch. Insect Biochem. Physiol. 27: 205-216.
- SCOTT, J. G. AND DONG, K. 1994. kdr-type resistance in the German cockroach, Blattella germanica. Comp. Biochem. Physiol. 109B: 191-198.
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Progress 01/01/93 to 12/30/93
Outputs A cytochrome P-450 was purified from abdominal microsomes of untreated and phenobarbital treated susceptible (S+) and insecticide-resistant (LPR) houseflies using HPLC purification procedures. The purified cytochrome P-450s exhibited the same apparent molecular masses (54,400 dalton) and could not be distinguished from each other on the basis of HPLC chromatographic properties, reduced CO-difference absorbance maxima (447 # 0.5 nm), or partial NH2-terminal sequences (MLLLLLLIVVTTLYIFAKL). Since these P450s were indistinguishable and were immunologically identical to cytochrome P450lpr we conclude that these P450s are in fact cytochrome P450lpr. The level of P-450lpr was increased 2-fold after PB exposure in the S+ strain, while the level of P-450lpr did not change in the LPR strain. Immunoinhibition of ECOD activity with anti-P-450lpr antiserum suggests that PB treatment in S+ house flies induced P-450lpr, and other forms of cytochrome P-450s with high activity toward
the substrate.
Impacts (N/A)
Publications
- HATANO, R., AND SCOTT, J.G. 1993. Anti-P450lpr antiserum inhibits the activation of chlorpyrifos to chlorpyrifos oxon in house fly microsomes. Pestic. Biochem. Physiol. 45:228-233.
- DONG, K., SCOTT, J.G., ET AL. 1993. (3H)batrachotoxinin A-20-alpha benzoate binding in synaptosomes from susceptible and kdr-type resistant German cockroaches, Blattella germanica (L.). Pestic. Biochem. Physiol. 46:141-148.
- SCOTT, J.G., ET AL. 1993. Tissue distr. of microsomal cytochrome P-450 monooxygenases and their induc. by phenobarbital in the insect. resis. LPR strain of house fly, Musca domestica L. Insect Biochem. Molec. Biol. 23:729-738.
- SCOTT, J.G. 1993. The cytochrome P450 microsomal monooxygenases of insects: recent advances, In: "Reviews in Pesticide Toxicology," R.M. Roe and R.J. Kuhr, eds., Toxicology Commun., Raleigh, NC. pp. 1-12.
- SCOTT, J.G., ET AL. 1993. Purification and characteriz. of a cytochrome P-450 from insect. suscep. and resis. strains of house fly, Musca domestica L., before & after phenobarbital exposure. Arch. Insect Biochem. Physiol. 24:1-19.
- HATANO, R., AND SCOTT, J.G. 1993. Characterization of (3H)abamectin binding in susceptible and abamectin resistant strains of house fly. J. Pestic. Sci. 18:281-284.
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Progress 01/01/92 to 12/30/92
Outputs We have recently purified a cytochrome P450, termed P450lpr, from the insecticide resistant LPR strain of house fly (Musca domestica). A polyclonal antiserum was raised, shown to be specific for P450lpr and used to characterize this P450. P450lpr was expressed at highest levels in adult LPR house flies, compared to larvae or pupae, and was found in both sexes. P450lpr was found at 44-fold higher levels in LPR than in susceptible flies. A single immuno-reactive band in denaturing gel electrophoresis, corresponding to P450lpr, was found in all house fly strains tested, with higher levels being found in resistant compared to susceptible strains. Anti-P450lpr inhibited P450 monooxygenase dependent in vitro deltamethrin metabolism in LPR microsomes indicating that P450lpr is involved in P450 monooxygenase dependent pyrethroid resistance.
Impacts (N/A)
Publications
- WHEELOCK, G.D., AND SCOTT, J.G. 1989. Simultaneous purification of a cytochrome P-450 and cytochrome b5 from the house fly Musca domestica L. Insect Biochem. 19:481-489.
- LEE, S.S.T., AND SCOTT, J.G. 1989. Microsomal cytochrome P450 monooxygenases in the house fly (Musca domestica L.): biochem. changes assoc. with insectic. resistance and phenobarbital induction. Pestic. Biochem. Physiol. 35:1-10.
- RAYMOND, M., HECKEL, D.G., AND SCOTT, J.G. 1989. Interactions between pesticide resistance genes: model and experiment. Genetics 123:543-551.
- LEE, S.S.T., AND SCOTT, J.G. 1989. An improved method for preparation, stabilization and storage of house fly (Diptera: Muscidae) microsomes. J. Econ. Entomol. 82:1559-1563.
- SCOTT, J.G., LEE, S.S.T., AND SHONO, T. 1990. Biochemical changes in the cytochrome P450 monooxygenases of seven insecticide-resistant house fly (Musca domestica L.) strains. Pestic. Biochem. Physiol. 36:127-134.
- SHONO, T., AND SCOTT, J.G. 1990. Autosomal sex-associated pyrethroid resistance in a strain of house fly (Diptera: Muscidae) with a male-determining factor on chromosome three. J. Econ. Entomol. 83:686-689.
- WHEELOCK, G.D., AND SCOTT, J.G. 1990. Immunological detection of cytochrome P450 from insecticide resistant and susceptible house flies (Musca domestica). Pestic. Biochem. Physiol. 38:130-139.
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Progress 01/01/91 to 12/30/91
Outputs An antiserum specific for house fly cytochrome P450lpr was investigated for its ability to inhibit cytochrome P450 monooxygenase dependent deltamethrin oxidation. Treatment of microsomes from pyrethroid resistant LPR house flies with anti-P450lpr antiserum inhibited 52% of the deltamethrin metabolism. Treatment of microsomes from susceptible (S+) flies with anti-P450lpr had no statistically significant effect. However, there was specific and statistically significant inhibition of metabolite production in both strains. Using LPR microsomes, seven NADPH-dependent products of (14C)-deltamethrin metabolism could be identified by thin layer chromatography followed by autoradiography, designated as B, C, D, E, F, G and H (origin). Metabolites B, C, D and H were the major metabolites. Formation of metabolites B, C and H were inhibited by anti-P450lpr while D was increased. In S+ microsomes, only metabolites C, D and E were consistently detected. In S+ microsomes,
anti-P450lpr inhibited formation of C and D while E was unchanged. This study suggests that P450lpr contributes to monooxygenase dependent deltamethrin resistance in LPR house flies.
Impacts (N/A)
Publications
- SCOTT, J.G. 1991. Insecticide resistance in insects. In "Handbook of Pest Management," D. Pimentel, ed., Vol 2. CRC Press, Boca Raton, FL pp. 663-677.
- FERGUSSON-KOLMES, L.A., SCOTT, J.G. and DENNEHY, T.J. 1991. Dicofol resistance in Tetranychus urticae (Acari: Tetranychidae): cross-resistance and pharmacokinetics. J. Econ. Entomol. 84:41-48.
- WHEELOCK, G.D. and SCOTT, J.G. 1991. Rapid microsome preparation from limited numbers of house flies (Diptera: Muscidae). Entomol. exp. Applic. (in press).
- WHEELOCK, G.D., KONNO, Y. and SCOTT, J.G. 1991. Expression of P450lpr is developmentally regulated and limited to house fly. J. Biochem. Toxicol. (in press).
- WHEELOCK, G.D. and SCOTT, J.G. 1991. The role of cytochrome P450lpr in deltamethrin metabolism by pyrethroid resistant and susceptible strains of house flies. Pestic. Biochem. Physiol. (Submitted).
- WHEELOCK, G.D. and SCOTT, J.G. 1991. Anti-P450lpr antiserum inhibits specific monooxygenase activities in LPR house fly microsomes. J. Exp. Zool. (Submitted).
- SCOTT, J.G. and WHEELOCK, G.D. 1992. Characterization of a cytochrome P450 responsible for pyrethroid resistance in the house fly. In "Molecular Basis of Insecticide Resistance,"...Amer. Chem. Soc. Washington, D.C. (submitted).
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Progress 01/01/90 to 12/30/90
Outputs Mechanisms and genetics of resistance to pyrethroid insecticides were investigated in a strain of house fly (ASPR) collected from a cattle ranch in Miyagi, Gunma Prefecture, Japan. Flies were selected in the laboratory with the pyrethroid insecticide permethrin. Both sexes were resistant to pyrethroids; however, females were 22- to 245-fold more resistant than males. Permethrin resistance could be partly suppressed by the monooxygenase inhibitor piperonyl butoxide in females, but not in males. In this strain, sex was determined by a male factor on the third autosome. The relationship of the autosomal male factor to the lower resistance levels observed in the males and the mechanisms of resistance expressed in each sex are discussed.
Impacts (N/A)
Publications
- SHONO, T. and SCOTT, J.G. 1990. Autosomal sex-associated pyrethroid resistance in a strain of house fly (Diptera: Muscidae) with a male-determining factor on chromosome three. J. Econ. Entomol. 83:686-689.
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Progress 01/01/88 to 12/30/88
Outputs We evaluated toxicity of 7 insecticides against the house fly, Musca domestica, and its important biological control agent, Urolepis rufipes. Toxicity to U. rufipes (based on LC50's) decreased as follows: dimethoate>permethrin>tetrachlorvinphos>fenvalerate> Pyrenone (pyrethrins + piperonyl butoxide) & dichlorvos>crotoxyphos. Male U. rufipes were 1.3-2.8 X more sensitive than females, seemingly due to smaller male size (1.7-fold). Toxicity (micrograms/vial) of the 7 insecticides to U. rufipes vs M. domestica revealed fenvalerate & crotoxyphos were more toxic to M. domestica; dichlorvos & Pyrenone more toxic to U. rufipes; permethrin, tetrachlorvinphos, & dimethoate equally toxic to both species. Toxicity of the same insecticides was evaluated against adult male & female Spalangia cameroni, an important biological control agent of fly pests. Insecticide toxicity decreased in order of dimethoate > crotoxyphos > permethrin & dichlorvos & Pyrenone > fenvalerate. Male S.
cameroni more sensitive than females to crotoxyphos, permethrin, & fenvalerate; females more sensitive than males to dichlorvos; no significant difference between LC50s of dimethoate & Pyrenone for each sex. Tetrachlorvinphos bioassay revealed a distinct plateau at ca. 55% mortality, suggesting presence of resistant individuals in this population. Comparison of S. cameroni and M. domestica toxicity data (micrograms/vial) revealed fenvalerate, permethrin & dimethoate were more toxic to M. domestica.
Impacts (N/A)
Publications
- SCOTT, J.G. and RUTZ, D.A. 1988. Comparative toxicities of seven insecticides to Musca domestica (L.) (Diptera:Muscidae) and Urolepis rufipes (Ashmead) (Hymenoptera:Pteromalidae). J. Econ. Entomol. 81:804-807.
- SCOTT, J.G. 1988. Pyrethroid insecticides. ISI Atlas Sci. Pharmacol. 2:125-128.
- SCOTT, J.G., D.A. RUTZ and J. WALCOTT. 1988. Comparative toxicity of seven insecticides to adult Spalangia cameroni Perkins. J. Agric. Entomol. 5:139-145.
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Progress 01/01/87 to 12/30/87
Outputs Investigations are currently underway in the Insect Toxicology Laboratory aimed at understanding how we can more effectively control insect pests and prevent the development of resistance to insecticides. Currently, we are studying several areas. (1) We are seeking to understand the biochemical genetics of the mixed-function oxidase sysem. This system is the primary means of metabolism of "foreign compounds" in most animals and is one of the primary means by which insects become resistant to insecticides. (2) We have conducted a statewide survey of dairies to determine the level of resistance to five commonly used insecticides. Resistance was found to be widespread and severe. (3) The effect of insecticides used for house fly control on dairies have been evaluated against four species of fly biological control agents. Of the seven insecticides tested fenvalerate was by far the best, having high toxicity to house flies and low toxicity to the biological control agents.
(4) Work has begun on identifying effective control measures for the carpenter ant, a serious pest of homes, and other wooden structures in the United States.
Impacts (N/A)
Publications
- SCOTT, J.G. 1987. Effect of temperature on the toxicity of S-bioallethrin and cypermethrin to susceptible and kdr-resistant Blattella germanica (L.) (Dictyoptera: Blattellidae). Bull. Entomol. Res. 77:431-435.
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Progress 08/01/86 to 12/30/86
Outputs Studies are currently under way in the following areas: (1) House flies have been collected from the Learn dairy in Horseheads, NY where control failures have been observed with a relatively new pyrethroid insecticide, permethrin. This study will expand next year and include other dairies to determine the extent of resistance in NY State. (2) Currently, studies are under way to investigate the mechanisms of resistance in the strain of house fly collected from the Learn dairy. Work is in the preliminary stage at this point, and thus there is nothing to report. (3) Two studies have been initiated to study the biochemistry of resistance to insecticides. In the first, the effect of temperature on the expression of kdr-resistance in the German cockroach was studied. Results showed that the effect of temperature varied from one pyrethroid insecticide to another. In a second study, the genetic isolation of factors coding for resistance has begun, but there are no data to
report as of yet.
Impacts (N/A)
Publications
- NO PUBLICATIONS TO REPORT THIS PERIOD.
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