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1.
Insect Mol Biol ; 20(2): 267-78, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21205278

RESUMO

Three genes encoding proteins showing sequence similarity and features typical of insect APNs were characterized in C. tremulae and designed as CtAPN1, CtAPN2 and CtAPN3. Expression analysis of the three C. tremulae APN genes showed that CtAPN2 transcript is more abundant in the fat body, whereas both CtAPN1 and CtAPN3 are specifically expressed in the midgut. Despite a similar genomic organization, lepidopteran and coleopteran APNs are phylogenetically distant, suggesting that APN gene duplication events occurred after these two insect orders split. Sequence and expression comparisons of CtAPN1, CtAPN2 and CtAPN3 cDNAs in a C. tremulae Bacillus thuringiensis (Bt)-susceptible and in a Bt-resistant strain did not show any polymorphism at the amino acid level or difference at the transcription level.


Assuntos
Proteínas de Bactérias , Antígenos CD13/genética , Besouros/enzimologia , Besouros/genética , Endotoxinas , Proteínas Hemolisinas , Controle Biológico de Vetores , Sequência de Aminoácidos , Animais , Bacillus thuringiensis/genética , Toxinas de Bacillus thuringiensis , Sistema Digestório/enzimologia , Corpo Adiposo/enzimologia , Feminino , Perfilação da Expressão Gênica , Estágios do Ciclo de Vida , Filogenia , Plantas Geneticamente Modificadas/genética , Populus/genética , Alinhamento de Sequência , Tribolium/genética
2.
Comp Biochem Physiol B Biochem Mol Biol ; 129(4): 837-41, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11435138

RESUMO

Two major forms of glutathione S-transferase are known in Drosophila melanogaster: GST D and GST 2. In the present paper we report the existence of a third major form of glutathione S-transferase in Drosophila simulans. Induction with phenobarbital revealed a different regulation of GST between these species. Despite the fact that these two species are closely related, there was a difference in the expression profile of the enzyme implicated in the detoxification system, suggesting variations in capacity to suit their environment.


Assuntos
Drosophila melanogaster/classificação , Drosophila melanogaster/enzimologia , Drosophila/classificação , Drosophila/enzimologia , Glutationa Transferase/biossíntese , Animais , Western Blotting , Glutationa Transferase/isolamento & purificação , Fenobarbital/farmacologia , Isoformas de Proteínas , Especificidade da Espécie
3.
Invert Neurosci ; 4(2): 85-94, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12488978

RESUMO

DSC1 encodes a putative voltage-sensitive sodium channel alpha subunit in Drosophila melanogaster. We generated polyclonal antibodies raised against part of the DSC1 sequence to characterize the size and the distribution of these channels in the adult fly. Immunoblotting experiments indicated that the protein has a molecular weight of about 270 kDa. We also showed that DSC1 channels are found only in the neurons of the fly. The density of channels was high in synaptic regions and in most of the axonal processes that connect the various structures of the CNS. No signal was observed in the cortical cell bodies where the para channels are mainly present. The most striking result concerns the widespread distribution of DSC1 channels in the PNS, as confirmed by experiments done with the monoclonal antibody 22C10. These results strongly suggest that DSC1 and para channels may have complementary roles, at least in the adult stage.


Assuntos
Sistema Nervoso Central/metabolismo , Sistema Nervoso Periférico/metabolismo , Canais de Sódio/metabolismo , Animais , Western Blotting , Drosophila melanogaster , Genes de Insetos , Cabeça/anatomia & histologia , Imuno-Histoquímica , Proteínas de Insetos , Fragmentos de Peptídeos/imunologia , Fragmentos de Peptídeos/metabolismo , Canais de Sódio/genética , Canais de Sódio/imunologia , Especificidade da Espécie
4.
Arch Insect Biochem Physiol ; 44(4): 143-50, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10918309

RESUMO

The larvicidal effects of polyphenols from dietary alder leaf litter were investigated in different field collections of three detritivorous Aedes taxa (Ae. detritus, Ae. cataphylla, Ae. rusticus) and compared to the cytochrome P450 monooxygenase, glutathione S-transferase, and esterase activities. Larvae from polyphenol-rich habitats had a higher tolerance for polyphenols and higher midgut cytochrome P450 and esterase activities than larvae from polyphenol-poor habitats. Furthermore, the role of P450 enzymes in the mechanism of resistance to alder polyphenols was suggested by the synergistic effect in vivo of piperonyl butoxide in the resistant Ae. rusticus. This confirms the importance of polyphenols to larval mosquito performance, and provides evidence for the importance of specific detoxification mechanisms for tolerance to dietary polyphenols. Arch.


Assuntos
Aedes/enzimologia , Flavonoides , Animais , Biotransformação , Sistema Enzimático do Citocromo P-450/metabolismo , Esterases/metabolismo , Larva , Fenóis/metabolismo , Folhas de Planta , Polímeros/metabolismo , Polifenóis , Árvores
5.
Biochem Biophys Res Commun ; 268(3): 677-82, 2000 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-10679264

RESUMO

Cytochrome P450 partial sequences were isolated by PCR using genomic DNA from two hymenopteran insects of agronomical importance, Trichogramma cacoeciae, a parasitoid wasp, and Apis mellifera, the honeybee. Four new P450 genes were identified: one honeybee gene belongs to the CYP4 family and was named CYP4G11; the three other genes were from Trichogramma and belong to the CYP4 family (CYP4G12) and to a novel family, the CYP48 one (CYP48A1 and CYP48A2). The four genes contain a short intron (72-95 bp) at the same position as already described for other insect species. The two genes CYP48A1 and CYP48A2 have a supernumary intron (57-71 bp) upstream the first one. Only the two CYP4 genes were constitutively transcribed, at a high level for CYP4G12 and at a low level for CYP4G11. No expression was observed for CYP48A1 and CYP48A2.


Assuntos
Abelhas/enzimologia , Abelhas/genética , Sistema Enzimático do Citocromo P-450/genética , Genes de Insetos , Vespas/enzimologia , Vespas/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , Primers do DNA/genética , Expressão Gênica , Íntrons , Dados de Sequência Molecular , Filogenia , Homologia de Sequência de Aminoácidos
6.
Comp Biochem Physiol B Biochem Mol Biol ; 122(2): 253-60, 1999 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10327614

RESUMO

Microsomal cytochrome P450-dependent lauric acid hydroxylase activities were characterized in liver, kidney, and intestinal mucosa of the sea bass (Dicentrarchus labrax). Microsomes from these organs generated (omega-1)-hydroxylauric acid and a mixture of positional isomers including (omega)-, (omega-2)-, (omega-3)- and (omega-4)-hydroxylauric acids, which were identified by RP-HPLC and GC-MS analysis. Peroxisome proliferators, such as clofibrate and especially di(2-ethylhexyl) phthalate, increased kidney microsomal lauric acid hydroxylase activities. The synthesis of 11-hydroxylauric acid was enhanced 5.3-fold in kidney microsomes. Liver microsomal lauric acid hydroxylase activities were weakly affected and no significant induction was found in small intestine microsomes from clofibrate or di(2-ethylhexyl) phthalate-treated fish. The differences in lauric acid metabolisation and the tissue-specific induction by peroxisome proliferators suggest the involvement of several P450s in this reaction. Incubations of liver and kidney microsomes with lauric acid analogues (11- or 10-dodecynoic acids) resulted in a time- and concentration-dependent loss of lauric acid hydroxylase activities. The induction of these activities in fish by phthalates, which are widely-distributed environmental pollutants, may be taken into consideration for the development of new biomarkers.


Assuntos
Bass/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Ácidos Láuricos/metabolismo , Proliferadores de Peroxissomos/farmacologia , Animais , Biomarcadores , Clofibrato/farmacologia , Sistema Enzimático do Citocromo P-450/efeitos dos fármacos , Dietilexilftalato/farmacologia , Ácidos Graxos Insaturados/metabolismo , Ácidos Graxos Insaturados/farmacologia , Hidroxilação , Intestino Delgado/efeitos dos fármacos , Intestino Delgado/metabolismo , Rim/efeitos dos fármacos , Rim/metabolismo , Cinética , Fígado/efeitos dos fármacos , Fígado/metabolismo , Microssomos/efeitos dos fármacos , Microssomos/metabolismo , Especificidade de Órgãos , Especificidade por Substrato
7.
Biochem Biophys Res Commun ; 258(1): 155-61, 1999 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-10222252

RESUMO

A cDNA sequence coding for a cytochrome P450 of the CYP4F subfamily was isolated from total RNA of sea bass kidney by rapid amplification of cDNA ends. The full length sequence coded for a protein of 526 amino acids. The amino acid sequence shared 39% to 56% residue identities with the mammalian CYP4F sequences, and thus was named CYP4F7 (accession number AF123541). RNA blot analysis using CYP4F7 cDNA as a probe indicated that the corresponding mRNA was only detected in kidney. Expression in the kidney was constitutive, and no induction of this mRNA was detected in this or other tissues, with any of the inducers tested, including peroxisome proliferators.


Assuntos
Sistema Enzimático do Citocromo P-450/genética , Rim/enzimologia , Oxigenases de Função Mista/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Bass , Clonagem Molecular , Citocromo P-450 CYP4A , DNA Complementar , Dados de Sequência Molecular , Filogenia , Homologia de Sequência de Aminoácidos
8.
Biochem Biophys Res Commun ; 251(1): 213-9, 1998 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-9790933

RESUMO

A full-length cDNA sequence was isolated from kidney total RNA of di(2-ethylhexyl) phthalate-treated sea bass by reverse-transcriptase polymerase chain reaction and then rapid amplification of cDNA ends. The deduced amino acid sequence, which has been named CYP4T2, shared 69 and 54.4% amino acid identity with rainbow trout CYP4T1 and rat CYP4B1, respectively. RNA blot analysis using the CYP4T2 cDNA as a probe indicated that the mRNA was rather abundant in kidney, and less so in liver, small intestine, and brain. Treatment of sea bass with peroxisome proliferators showed marked tissue-specific induction. CYP4 inducers clofibrate, di(2-ethylhexyl) phthalate (DEHP), and 2,4-dichlorophenoxy acetic acid (2,4-D) were administered by intraperitoneal injection. The strongest induction was found in kidney after a DEHP treatment (6.5-fold) or a 2,4-D treatment (9-fold), while no induction was observed in liver.


Assuntos
Hidrocarboneto de Aril Hidroxilases , Sistema Enzimático do Citocromo P-450/genética , Rim/enzimologia , Ácidos Ftálicos/farmacologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Bass , Clonagem Molecular , Sistema Enzimático do Citocromo P-450/biossíntese , Sistema Enzimático do Citocromo P-450/isolamento & purificação , Dados de Sequência Molecular , Oncorhynchus mykiss , Filogenia , Ratos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA
9.
Philos Trans R Soc Lond B Biol Sci ; 353(1376): 1701-5, 1998 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-10021770

RESUMO

Cytochrome P450 monooxygenases are involved in many cases of resistance of insects to insecticides. Resistance has long been associated with an increase in monooxygenase activities and with an increase in cytochrome P450 content. However, this increase does not always account for all of the resistance. In Drosophila melanogaster, we have shown that the overproduction of cytochrome P450 can be lost by the fly without a corresponding complete loss of resistance. These results prompted the sequencing of a cytochrome P450 candidate for resistance in resistant and susceptible flies. Several mutations leading to amino-acid substitutions have been detected in the P450 gene CYP6A2 of a resistant strain. The location of these mutations in a model of the 3D structure of the CYP6A2 protein suggested that some of them may be important for enzyme activity of this molecule. This has been verified by heterologous expression of wild-type and mutated cDNA in Escherichia coli. When other resistance mechanisms are considered, relatively few genetic mutations are involved in insecticide resistance, and this has led to an optimistic view of the management of resistance. Our observations compel us to survey in more detail the genetic diversity of cytochrome P450 genes and alleles involved in resistance.


Assuntos
Sistema Enzimático do Citocromo P-450/genética , Insetos/enzimologia , Insetos/genética , Resistência a Inseticidas/genética , Resistência a Inseticidas/fisiologia , Substituição de Aminoácidos , Animais , Família 6 do Citocromo P450 , Proteínas de Drosophila , Drosophila melanogaster/efeitos dos fármacos , Drosophila melanogaster/enzimologia , Drosophila melanogaster/genética , Escherichia coli/genética , Expressão Gênica , Genes de Insetos , Insetos/efeitos dos fármacos , Modelos Biológicos , Mutação
10.
Artigo em Inglês | MEDLINE | ID: mdl-9972466

RESUMO

A cDNA encoding for cytochrome P450 1A has been cloned in the marine teleost fish Dicentrarchus labrax. This fish, common in the Mediterranean, was chosen since it is considered a good sentinel species. Moreover, biomarkers of exposure to organic contaminants (such as EROD) are often measured in this species and make it possible to evaluate the quality of waters. For cloning purposes, RNAs were extracted from the liver of benzo[a]pyrene (BaP)-treated animals and used as template in degenerate RT-PCR. The cDNA product was cloned and used for the design of highly stringent primers that were utilized in Rapid Amplification of cDNA Ends (RACE) PCR. The cloned cDNA hybridizes with a 2.7 kb mRNA which is induced by treatment of the fish with BaP, a classical CYP1A inducer. The closest sequences found in data banks belong to fish CYP1A.


Assuntos
Sistema Enzimático do Citocromo P-450/genética , Peixes/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Northern Blotting , Clonagem Molecular , DNA Complementar , Dados de Sequência Molecular , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Homologia de Sequência de Aminoácidos
11.
Artigo em Inglês | MEDLINE | ID: mdl-9972473

RESUMO

We analysed Drosophila melanogaster cytochrome P450s (P450) through the measurements of four enzymatic activities: ethoxycoumarin-O-deethylase, ethoxyresorufin-O-deethylase, lauric acid hydroxylation, and testosterone hydroxylation. We did these measurements in two Drosophila strains: one is susceptible to insecticides (Cantons) and the other is resistant to insecticides by enhanced P450 activities (RDDTR). In addition, we also treated the flies with eight chemicals (beta-naphtoflavone, benzo-alpha-pyrene, 3-methylcholanthrene, phenobarbital, aminopyrine, rifampicin, prochloraz, and clofibrate) known to induces genes from the families CYP1, CYP2, CYP3, CYP4, and CYP6. Metabolisation of all the substrates by P450 from flies microsomes was observed. The chemicals had different effects on these activities, ranging from induction to inhibition. The effects of these chemicals varied with the strains as most of them were ineffective on the RDDTR strain. The results showed that P450-dependent activities are numerous in Drosophila. Regulation features of these activities are complex. The availability of mutant strains as RDDTR should allow fundamental studies of P450 in insects.


Assuntos
Sistema Enzimático do Citocromo P-450/biossíntese , Drosophila melanogaster/enzimologia , Resistência a Inseticidas , Animais , Indução Enzimática , Hidroxilação , Ácidos Láuricos/metabolismo , Testosterona/metabolismo
12.
DNA Cell Biol ; 16(11): 1345-56, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9407006

RESUMO

The cytochrome P450 gene Cyp6a2 from Drosophila melanogaster is located on the right arm of chromosome 2 at position 43A1-2 and comprises two exons separated by a 69-bp intron. Phenobarbital treatment of flies leads to a rapid increase in the level of CYP6A2 mRNA and to an increased production of the CYP6A2 protein. DNA from the Cyp6a2 promoter region was functional when linked to a luciferase reporter gene and transfected into D. melanogaster Schneider cells. Moreover, a dose-dependent induction of luciferase activity by phenobarbital indicated that elements necessary for phenobarbital induction are located within 428 bp of the translation start site. Heterologous expression of the CYP6A2 protein in lepidopteran cells infected with a Cyp6a2-recombinant baculovirus was observed by Western blotting of cell lysates and by spectral characterization of the reduced-CO complex of the P450. The CYP6A2 protein produced in this system metabolized aldrin and heptachlor to their epoxides and metabolized the insecticide diazinon by desulfuration to diazoxon and by oxidative ester cleavage to 2-isopropyl-4-methyl-6-hydroxypyrimidine. Metabolism in lysates of cells infected with recombinant baculovirus was greatly enhanced by the addition of purified housefly NADPH cytochrome P450 reductase and cytochrome b5. These results show that CYP6A2 catalyzes the metabolism of organophosphorus insecticides and they implicate Cyp6a2 overexpression in metabolic resistance. The Cyp6a2 gene appears to be a suitable model for a genetic analysis of the phenobarbital induction process.


Assuntos
Sistema Enzimático do Citocromo P-450/genética , Drosophila melanogaster/enzimologia , Expressão Gênica , Fenobarbital/farmacologia , Aldrina/farmacologia , Sequência de Aminoácidos , Animais , Baculoviridae , Sequência de Bases , Catálise , Sistema Enzimático do Citocromo P-450/biossíntese , Família 6 do Citocromo P450 , DNA/química , Proteínas de Drosophila , Drosophila melanogaster/genética , Indução Enzimática , Vetores Genéticos , Heptacloro/farmacologia , Moscas Domésticas/enzimologia , Moscas Domésticas/genética , Inseticidas/farmacologia , Dados de Sequência Molecular , Fases de Leitura Aberta , Regiões Promotoras Genéticas
13.
Toxicol Appl Pharmacol ; 144(1): 177-82, 1997 May.
Artigo em Inglês | MEDLINE | ID: mdl-9169082

RESUMO

In spite of increasing numbers of insecticides used in agriculture, there are serious concerns regarding the potential risks of exposure to these agents. Carbaryl is one of the most important carbamate insecticides and has been used for about 30 years to control a wide range of pests. The study was designed to investigate if, among various insecticides currently used in world agriculture, this compound could induce human CYP1A1, an enzyme known to play an important role in the chemical activation of xenobiotics to genotoxic derivatives. Studies on HepG2 and HaCaT cell lines showed that carbaryl is capable of increasing, in a dose-dependent manner, both the ethoxyresorufin rufin-O-dec, O-deethylase activity and the steady-state concentrations of CYP1A1 mRNA, suggesting a transcriptional activation of this gene. When alpha-naphthoflavone, a partial Ah receptor (AhR) antagonist, and 8-methoxypsoralen, which interferes with the binding of activated AhR to the xenobiotic responsive element (XRE), were added to the cultures, CYP1A1 induction was suppressed. However, competitive binding studies using the 9S enriched fraction of human cytosol indicated that carbaryl did not displace [3H]TCDD from AhR. These data, together with the activation of a XRE-directed CAT reporter gene by carbaryl, suggest that induction of CYP1A1 involves the participation of the AhR and the XRE, but is not mediated by a direct carbaryl-receptor interaction. An alternative ligand-independent mechanism should be considered. Therefore, although carbaryl concentration in food is very low, care should be taken because of its possible adverse effects in human health through liver and skin, given the well established toxicological importance of CYP1A1 induction.


Assuntos
Carbaril/farmacologia , Citocromo P-450 CYP1A1/genética , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Inseticidas/farmacologia , Receptores de Hidrocarboneto Arílico/metabolismo , Benzoflavonas/farmacologia , Carbaril/metabolismo , Linhagem Celular , Cloranfenicol O-Acetiltransferase/genética , Citocromo P-450 CYP1A1/metabolismo , Humanos , Ligantes , Metoxaleno/farmacologia , RNA Mensageiro/genética
14.
J Econ Entomol ; 90(6): 1514-20, 1997 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9461846

RESUMO

Studies were conducted between 1993 and 1996 using 3 natural grape vine populations, 1 susceptible laboratory strain, and 1 resistant selected strain of Drosophila melanogaster L. In vitro monooxygenase activity (ethoxycoumarine-O-deethylation) (ECOD) was recorded from microsomal fractions of all strains. Results varied over a 6-fold range between susceptible laboratory Canton and resistant selected RDDT strains and over a 2-fold range between the Canton strain and natural populations of flies. Few significant variations of ECOD activity were detected among the natural populations despite many insecticide treatments, but activities were significantly correlated with toxicological tolerance to 5 of the 15 insecticides (deltamethrin, fipronil, chlorpyriphos ethyl, DDT, and diazinon). Moreover, immunoblotting responses of microsomal protein encoded by Cyp6A2 showed that the levels of expression were quantitatively correlated with toxicological tolerance to almost the same group of insecticides (deltamethrin, fipronil, chlorpyriphos ethyl, DDT, fenvalerate, and fenthion). However, the level of CYP6A2 expression in some natural strains (still weakly resistant) was almost comparable with one of the resistant strains. In vivo monooxygenase activity recorded in individual abdomens of flies showed that frequency distributions of ECOD activity in natural populations overlapped those of the resistant and laboratory strains, which were much narrower. Substantial and fast frequency changes (of the narrowness) that obtained in laboratory were related to either the time of rearing of 1 of the natural populations or selecting this population with an insecticide that has a toxicology correlated with both of the monooxygenase signs measured. Perspectives on using the CYP6A2 expression and ECOD activity for detecting a resistance mechanism by cytochrome P450 in field populations are discussed.


Assuntos
Sistema Enzimático do Citocromo P-450/metabolismo , Drosophila melanogaster/enzimologia , Inseticidas , Animais , Western Blotting , Sistema Enzimático do Citocromo P-450/biossíntese , Família 6 do Citocromo P450 , Proteínas de Drosophila , Resistência a Inseticidas , Nitrilas , Oxigenases/metabolismo , Piretrinas , Rosales
15.
Insect Biochem Mol Biol ; 26(7): 697-703, 1996 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8995791

RESUMO

The importance of cytochrome P450s in the biology of cells or organisms is clearly established. While numerous studies concern vertebrates, little is known about invertebrates cytochrome P450s. In this paper, we have focused on CYP6A2 gene expression in Drosophila melanogaster. We show the expression of this cytochrome P450 gene in the Canton(s) strain (wild type) to be under the control of phenobarbital. In adults treated with phenobarbital, this gene is transcribed in the midgut, the pericuticular fat bodies and the Malpighian tubules. The induction factor is 15. In the RDDTR strain of Drosophila melanogaster, which is resistant to the insecticide DDT, this gene is constitutively overexpressed in the same tissues (overexpression factor is 6 relative to untreated Canton(s) flies). Phenobarbital is not as effective on RDDTR (induction factor is 2.5 relative to untreated RDDTR flies) as on wild type strains.


Assuntos
Sistema Enzimático do Citocromo P-450/genética , DDT , Drosophila melanogaster/enzimologia , Resistência a Inseticidas , Fenobarbital , Animais , Northern Blotting , Southern Blotting , Sistema Enzimático do Citocromo P-450/metabolismo , Expressão Gênica
16.
Anal Biochem ; 229(1): 86-91, 1995 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-8533900

RESUMO

We developed a method for measuring ethoxycoumarin deethylase (ECOD) activity using a single Drosophila abdomen. The activities obtained were well correlated with the classic method from microsomes (r = 0.902). This new method, performed in microtitration plates, was at least six times more sensitive compared to the conventional cuvet fluorometric one. Moreover, it was possible among a large number of insects to differentiate those with low or high ECOD activities. This improved procedure has been checked upon crosses between resistant strain (with high ECOD activity) and susceptible strain (with low ECOD activity). The results demonstrate the possible separation of resistant phenotypes and emphasize the importance of this approach in assessing the spreading of insecticide resistance in natural populations of insects.


Assuntos
O-Dealquilase 7-Alcoxicumarina/análise , Drosophila melanogaster/enzimologia , Espectrometria de Fluorescência/métodos , Abdome , Animais , Drosophila melanogaster/efeitos dos fármacos , Drosophila melanogaster/genética , Estudos de Avaliação como Assunto , Resistência a Inseticidas/genética , Microssomos/enzimologia , Sensibilidade e Especificidade , Espectrometria de Fluorescência/instrumentação , Espectrometria de Fluorescência/estatística & dados numéricos
17.
Arch Insect Biochem Physiol ; 28(4): 325-38, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-7711301

RESUMO

In vitro bioassays were used to analyze the metabolism of the 11-dodecenoic acid (11-DDNA) by microsomes prepared from Drosophila melanogaster RalDDTR strain. 11-DDNA is metabolized to 11,12-epoxylauric acid (epoxyLA) in a NADPH-dependent way. The microsomal production of epoxyLA reaches a plateau very quickly, suggesting the occurrence of an enzyme inactivation process. After incubation of microsomes with (1-14C)11-DDNA, three proteins of Mr approximately 50 kDa were labeled. 11-DDNA inhibits the microsomal metabolism of lauric acid and 7-ethoxycoumarin in a time and NADPH-dependent process. An inhibition of metabolites generated from DDT and testosterone was also obtained but at higher concentrations. These results are discussed according to the fact that RalDDTR is an insecticide resistant strain characterized as a high metabolizer of the insecticide DDT and also of lauric acid, testosterone, and ethoxycoumarin.


Assuntos
Inibidores das Enzimas do Citocromo P-450 , Inibidores Enzimáticos/metabolismo , Ácidos Graxos Monoinsaturados/metabolismo , Microssomos/metabolismo , Oxigenases/antagonistas & inibidores , Alcenos , Animais , Sistema Enzimático do Citocromo P-450/metabolismo , Drosophila melanogaster , Hidroxilação , Estrutura Molecular , Oxigenases/metabolismo , Especificidade por Substrato , Testosterona/metabolismo
18.
Insect Biochem Mol Biol ; 23(3): 381-90, 1993 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8387373

RESUMO

In Drosophila, the para gene has been shown to encode a functional voltage-dependent sodium channel. We used a cDNA clone to study the distribution of its transcripts by in situ mRNA hybridization on adult fly sections. These transcripts are found in cortical regions of the central nervous system and in the eyes. On immunoblots, antibodies raised against expression products of part of the gene recognize a polypeptide of M(r) approximately 270,000 in head membranes. Immunolocalization experiments indicate that anti-para antibodies bind to cortical regions of the brain and give heavy signals in the eyes. Immunohistochemistry was also performed on napts and seits1, two mutant Drosophila strains known to be defective in sodium channel activity. Only napts flies displayed a decrease in the expression of the para protein.


Assuntos
Drosophila/genética , Animais , Expressão Gênica , Imunoquímica , Hibridização In Situ , Mutação , RNA Mensageiro/genética , Canais de Sódio/genética , Canais de Sódio/imunologia , Transcrição Gênica
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