The Experts below are selected from a list of 189 Experts worldwide ranked by ideXlab platform
Rene Feyereisen - One of the best experts on this subject based on the ideXlab platform.
-
cyp12a1 a mitochondrial cytochrome p450 from the House Fly
Archives of Biochemistry and Biophysics, 1998Co-Authors: Victor M Guzov, Gopalan C Unnithan, Alexey A Chernogolov, Rene FeyereisenAbstract:Abstract Eukaryotic P450 proteins are membrane proteins found predominantly in the endoplasmic reticulum. In vertebrates, several biosynthetic P450s are found in mitochondria as well. We cloned three putative insect mitochondrial P450s from larval House Fly cDNA. These P450s are members of a new P450 family, CYP12. The CYP12 proteins are most closely related to the mammalian mitochondrial P450 of the CYP11, CYP24, and CYP27 families. The most abundant cDNA, CYP12A1, was expressed in Escherichia coli and purified. NADPH-dependent reduction of CYP12A1 was rapid and efficient with the bovine mitochondrial proteins adrenodoxin reductase and adrenodoxin as electron transfer partners. In contrast, House Fly microsomal NADPH cytochrome P450 reductase reduced CYP12A1 only poorly. In a reconstituted system with the bovine mitochondrial electron donors, CYP12A1 metabolized a variety of insecticides and other xenobiotics, but did not metabolize ecdysteroids, juvenoids, or fatty acids. Subcellular localization of CYP12A1 by immunogold histochemistry established the mitochondrial nature of this protein. CYP12A1 mRNA levels are constitutively higher in an insecticide-resistant strain than in a susceptible strain, and this trait maps to chromosome II in the House Fly, where the constitutive overexpression of the pesticide-metabolizing microsomal CYP6A1 also maps. Multiple mitochondrial P450s have evolved in insects and may play a role in the metabolism of xenobiotics in addition to their possibly ancestral functions in steroidogenesis.
-
Molecular cloning, overexpression in Escherichia coli, structural and functional characterization of House Fly cytochrome b5.
Journal of Biological Chemistry, 1996Co-Authors: Victor M Guzov, Heather L. Houston, Marat B. Murataliev, F. Ann Walker, Rene FeyereisenAbstract:Abstract A microsomal cytochrome b5 cDNA from the House Fly, Musca domestica, was cloned and sequenced. The deduced amino acid sequence of the full-length House Fly cytochrome b5 (134 residues) is 48% identical to that of rat microsomal cytochrome b5. The House Fly cytochrome b5 protein was overexpressed in Escherichia coli, purified, and characterized. Absorption and EPR spectroscopy reveal properties very similar to cytochromes b5 from vertebrates. NMR spectra indicate that the orientation of the heme in the protein relative to its α,γ meso axis is about 1:1. A redox potential of −26 mV versus standard hydrogen electrode was measured by cyclic voltammetry on a modified gold electrode in the presence of hexamminechromium(III) chloride. The cytochrome b5 is reduced by House Fly cytochrome P450 reductase in a reconstituted system at a high rate (5.5 s−1), and it stimulates heptachlor epoxidation when reconstituted with House Fly cytochrome P450 reductase, cytochrome P450 6A1, phospholipid, and detergent. Cytochrome b5 decreases the apparent Km for P450 reductase and increases the Vmax for heptachlor epoxidation at constant cytochrome P450 6A1 concentrations. The results indicate that cytochrome b5 stimulates a step following the first electron transfer during cytochrome P450 6A1 turnover.
-
The cDNA and deduced protein sequence of House Fly NADPH-cytochrome P450 reductase
Insect Biochemistry and Molecular Biology, 1993Co-Authors: J.f. Koener, F.a. Cariño, Rene FeyereisenAbstract:Abstract Antisera to purified House Fly NADPH-cytochrome P450 reductase were used to select cDNA clones from an expression library of abdomens of phenobarbital-treated House flies. A partical cDNA of 1841 bp containing a TAG termination codon, a consensus polyadenylation site and 269 bp of 3′ untranslated sequence was obtained. Sequencing of a genomic clone coupled with mRNA sequencing yielded the complete coding sequence including the starting ATG. The resulting open reading frame of 2013 nucleotides codes for a protein of 671 residues. The native reductase apoprotein has a molecular weight of 76,366 and the deduced molecular weight of the holoenzyme (i.e. with 1 mol of FAD and FMN) is 77,608. The sequence of the House Fly P450 reductase protein is highly similar to that of rabbit liver, the overall amino acid positional identity among eukaryotic P450 reductases is about 25%. The P450 reductase gene of 19–23 kb was located on chromosome III, as shown by comparison of RFLP-patterns of the P450 reductase gene in two House Fly strains and their hybrids.
Richard P. Meisel - One of the best experts on this subject based on the ideXlab platform.
-
the House Fly y chromosome is young and minimally differentiated from its ancient x chromosome partner
Genome Research, 2017Co-Authors: Richard P. Meisel, Christopher A. GonzalesAbstract:: Canonical ancient sex chromosome pairs consist of a gene rich X (or Z) Chromosome and a male-limited (or female-limited) Y (or W) Chromosome that is gene poor. In contrast to highly differentiated sex chromosomes, nascent sex chromosome pairs are homomorphic or very similar in sequence content. Nascent sex chromosomes can arise if an existing sex chromosome fuses to an autosome or an autosome acquires a new sex-determining locus/allele. Sex chromosomes often differ between closely related species and can even be polymorphic within species, suggesting that nascent sex chromosomes arise frequently over the course of evolution. Previously documented sex chromosome transitions involve changes to both members of the sex chromosome pair (X and Y, or Z and W). The House Fly has sex chromosomes that resemble the ancestral Fly karyotype that originated ∼100 million yr ago; therefore, the House Fly is expected to have X and Y Chromosomes with different gene content. We tested this hypothesis using whole-genome sequencing and transcriptomic data, and we discovered little evidence for genetic differentiation between the X and Y in House Fly. We propose that the House Fly has retained the ancient X Chromosome, but the ancestral Y was replaced by an X Chromosome carrying a new male determining gene. Our proposed hypothesis provides a mechanism for how one member of a sex chromosome pair can experience evolutionary turnover while the other member remains unaffected.
-
The House Fly Y Chromosome is Young and Undifferentiated from its Ancient X Chromosome Partner
bioRxiv, 2016Co-Authors: Richard P. Meisel, Christopher A. GonzalesAbstract:Ancient or canonical sex chromosome pairs consist of a gene rich X (or Z) chromosome and a male- (or female-) limited Y (or W) chromosome that is gene poor. In contrast to highly differentiated sex chromosomes, nascent sex chromosome pairs are homomorphic or very similar in sequence content. Nascent sex chromosomes arise frequently over the course of evolution, as evidenced by differences in sex chromosomes between closely related species and sex chromosome polymorphisms within species. Sex chromosome turnover typically occurs when an existing sex chromosome becomes fused to an autosome or an autosome acquires a new sex-determining locus/allele. Previously documented sex chromosome transitions involve changes to both members of the sex chromosome pair (X and Y, or Z and W). The House Fly has sex chromosomes that resembles the ancestral Fly karyotype that originated ~100 million years ago, and therefore House Fly is expected to have differentiated X and Y chromosomes. We tested this hypothesis using whole genome sequencing and transcriptomic data, and we surprisingly discovered little evidence for X-Y differentiation in House Fly. We propose that House Fly has retained the ancient X chromosome, but the ancestral Y was replaced by an X chromosome carrying a male determining gene. In this evolutionary scenario, the House Fly has an ancient X chromosome that is partnered with with a neo-Y chromosome. This example of sex chromosome recycling illustrates how one member of a sex chromosome pair can experience evolutionary turnover while the other member remains unaffected.
-
is multifactorial sex determination in the House Fly musca domestica l stable over time
Journal of Heredity, 2016Co-Authors: Richard P. Meisel, Alec C Gerry, Taira Davey, Toshio Shono, Jeffrey G. ScottAbstract:: Sex determination pathways evolve rapidly, usually because of turnover of master regulatory genes at the top of the developmental pathway. Polygenic sex determination is expected to be a transient state between ancestral and derived conditions. However, polygenic sex determination has been observed in numerous animal species, including the House Fly, Musca domestica House Fly males carry a male-determining factor (M) that can be located on any chromosome, and an individual male may have multiple M factors. Females lack M and/or have a dominant allele of the Md-tra gene (Md-tra D ) that acts as a female-determining locus even in the presence of multiple copies of M. We found the frequency and linkage of M in House flies collected in Chino, CA (USA) was relatively unchanged between 1982 and 2014. The frequency of females with Md-tra D in the 2014 collection was 33.6% (n = 140). Analysis of these results, plus previously published data, revealed a strong correlation between the frequencies of Md-tra D and multiple M males, and we find that these populations are expected to have balanced sex ratios. We also find that fitness values that allow for the invasion and maintenance of multiple sex determining loci suggest that sexually antagonistic selection could be responsible for maintaining polygenic sex determination in House Fly populations. The stability over time and equilibrium frequencies within populations suggest the House Fly polygenic sex determination system is not in transition, and provide guidance for future investigations on the factors responsible for the polymorphism.
Jeffrey G. Scott - One of the best experts on this subject based on the ideXlab platform.
-
is multifactorial sex determination in the House Fly musca domestica l stable over time
Journal of Heredity, 2016Co-Authors: Richard P. Meisel, Alec C Gerry, Taira Davey, Toshio Shono, Jeffrey G. ScottAbstract:: Sex determination pathways evolve rapidly, usually because of turnover of master regulatory genes at the top of the developmental pathway. Polygenic sex determination is expected to be a transient state between ancestral and derived conditions. However, polygenic sex determination has been observed in numerous animal species, including the House Fly, Musca domestica House Fly males carry a male-determining factor (M) that can be located on any chromosome, and an individual male may have multiple M factors. Females lack M and/or have a dominant allele of the Md-tra gene (Md-tra D ) that acts as a female-determining locus even in the presence of multiple copies of M. We found the frequency and linkage of M in House flies collected in Chino, CA (USA) was relatively unchanged between 1982 and 2014. The frequency of females with Md-tra D in the 2014 collection was 33.6% (n = 140). Analysis of these results, plus previously published data, revealed a strong correlation between the frequencies of Md-tra D and multiple M males, and we find that these populations are expected to have balanced sex ratios. We also find that fitness values that allow for the invasion and maintenance of multiple sex determining loci suggest that sexually antagonistic selection could be responsible for maintaining polygenic sex determination in House Fly populations. The stability over time and equilibrium frequencies within populations suggest the House Fly polygenic sex determination system is not in transition, and provide guidance for future investigations on the factors responsible for the polymorphism.
-
Use of quantitative real-time polymerase chain reaction to estimate the size of the House-Fly Musca domestica genome.
Insect Molecular Biology, 2006Co-Authors: Jeffrey G. ScottAbstract:House-flies, Musca domestica, are carriers of more than 100 devastating diseases that have severe consequences for human and animal health. A key bottleneck to progress in controlling the devastating human diseases transmitted by House-flies is lack of knowledge of the basic molecular biology of this species. However, before sequencing of the House-Fly genome can be seriously considered it is important to know the size of the genome. In this paper, we used quantitative real-time polymerase chain reaction to calculate genome size of the House-Fly in side-by-side experiments with Drosophila melanogaster (known genome size of 180 Mb). Our results indicate the size of the House-Fly genome is 295 +/- 10 Mb and that of D. melanogaster is 184 Mb. Thus, the House-Fly genome is only about 1.6-fold larger than the genome of D. melanogaster. This indicates that the size of the House-Fly genome makes it an excellent candidate for whole genome sequencing and that quantitative real-time polymerase chain reaction is an accurate method for the estimation of the size of insect genomes.
-
Inhibitors of CYP6D1 in House Fly microsomes.
Insect Biochemistry and Molecular Biology, 1996Co-Authors: Jeffrey G. ScottAbstract: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, beta-naphthoflavone, piperonyl butoxide and 5-methoxypsoralen. The highest selectivity for inhibition of CYP6D1 was seen for 5-methoxypsoralen, xanthotoxin, beta-naphthoflavone, 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.
-
Anti‐P450lpr antiserum inhibits specific monooxygenase activities in LPR House Fly microsomes
Journal of Experimental Zoology, 1992Co-Authors: Geoffrey D. Wheelock, Jeffrey G. ScottAbstract:Monooxygenase activity in microsomes from the LPR strain of House Fly (Musca domestica L.) was inhibited by anti-P450lpr, an antiserum specific for House Fly cytochrome P450lpr, Anti-P450lpr did not inhibit House Fly cytochrome P450 reductase or rat cytochrome P450 monooxygenase assays, consistent with specific inhibition of P450lpr. Anti-P450lpr inhibited the ability of cytochrome P450 reductase to reduce carbon monoxide treated LPR microsomal cytochrome P450, up to 49% of the total, showing that inhibition of cytochrome P450 reduction is the major mechanism of inhibition. Anti-P450lpr inhibited 98% of methoxyresorufin-O-demethylase activity and all the benzo(a)pyrene hydroxylase activity in LPR microsomes, but none of the pentoxyresorufin-O-dealkylase activity. The antiserum partially inhibited ethoxyresorufin-O-dealkylase and ethoxycoumarin-O-dealkylase activity. These results demonstrate that methoxyresorufin-O-demethylase activity and benzo(a)pyrene hydroxylase activity are characteristic substrates for P450lpr activity in the LPR strain of House Fly. © 1992 Wiley-Liss, Inc.
-
Expression of cytochrome P-450lpr is developmentally regulated and limited to House Fly.
Journal of Biochemical Toxicology, 1991Co-Authors: Geoffrey D. Wheelock, Yasuhiko Konno, Jeffrey G. ScottAbstract:Expression of House Fly cytochrome P-450lpr was examined using immunoblotting in male and female adult LPR House flies, mixed sex adult House flies at 12 different ages, larvae, and pupae. P-450lpr was expressed in both male and female adult House flies. P-450lpr was clearly present in all adult stages examined, was barely detectable in pupae, and could not be detected in larvae. Thus, cytochrome P-450lpr is developmentally regulated and present in both sexes of House Fly. Expression of cytochrome P-450, immunologically homologous to House Fly cytochrome P-450lpr was examined in other species using immunoblot analysis. Eleven animal species were tested in the orders Diptera, Hymenoptera, Lepidoptera, Orthoptera, Acari, and Rodentia, using microsomes in some species from both induced and noninduced animals or insecticide-resistant and susceptible strains. P-450lpr appears to be restricted to House flies, as none of these species contained cytochrome P-450 that reacted with antiserum to cytochrome P-450lpr.
Victor M Guzov - One of the best experts on this subject based on the ideXlab platform.
-
cyp12a1 a mitochondrial cytochrome p450 from the House Fly
Archives of Biochemistry and Biophysics, 1998Co-Authors: Victor M Guzov, Gopalan C Unnithan, Alexey A Chernogolov, Rene FeyereisenAbstract:Abstract Eukaryotic P450 proteins are membrane proteins found predominantly in the endoplasmic reticulum. In vertebrates, several biosynthetic P450s are found in mitochondria as well. We cloned three putative insect mitochondrial P450s from larval House Fly cDNA. These P450s are members of a new P450 family, CYP12. The CYP12 proteins are most closely related to the mammalian mitochondrial P450 of the CYP11, CYP24, and CYP27 families. The most abundant cDNA, CYP12A1, was expressed in Escherichia coli and purified. NADPH-dependent reduction of CYP12A1 was rapid and efficient with the bovine mitochondrial proteins adrenodoxin reductase and adrenodoxin as electron transfer partners. In contrast, House Fly microsomal NADPH cytochrome P450 reductase reduced CYP12A1 only poorly. In a reconstituted system with the bovine mitochondrial electron donors, CYP12A1 metabolized a variety of insecticides and other xenobiotics, but did not metabolize ecdysteroids, juvenoids, or fatty acids. Subcellular localization of CYP12A1 by immunogold histochemistry established the mitochondrial nature of this protein. CYP12A1 mRNA levels are constitutively higher in an insecticide-resistant strain than in a susceptible strain, and this trait maps to chromosome II in the House Fly, where the constitutive overexpression of the pesticide-metabolizing microsomal CYP6A1 also maps. Multiple mitochondrial P450s have evolved in insects and may play a role in the metabolism of xenobiotics in addition to their possibly ancestral functions in steroidogenesis.
-
Molecular cloning, overexpression in Escherichia coli, structural and functional characterization of House Fly cytochrome b5.
Journal of Biological Chemistry, 1996Co-Authors: Victor M Guzov, Heather L. Houston, Marat B. Murataliev, F. Ann Walker, Rene FeyereisenAbstract:Abstract A microsomal cytochrome b5 cDNA from the House Fly, Musca domestica, was cloned and sequenced. The deduced amino acid sequence of the full-length House Fly cytochrome b5 (134 residues) is 48% identical to that of rat microsomal cytochrome b5. The House Fly cytochrome b5 protein was overexpressed in Escherichia coli, purified, and characterized. Absorption and EPR spectroscopy reveal properties very similar to cytochromes b5 from vertebrates. NMR spectra indicate that the orientation of the heme in the protein relative to its α,γ meso axis is about 1:1. A redox potential of −26 mV versus standard hydrogen electrode was measured by cyclic voltammetry on a modified gold electrode in the presence of hexamminechromium(III) chloride. The cytochrome b5 is reduced by House Fly cytochrome P450 reductase in a reconstituted system at a high rate (5.5 s−1), and it stimulates heptachlor epoxidation when reconstituted with House Fly cytochrome P450 reductase, cytochrome P450 6A1, phospholipid, and detergent. Cytochrome b5 decreases the apparent Km for P450 reductase and increases the Vmax for heptachlor epoxidation at constant cytochrome P450 6A1 concentrations. The results indicate that cytochrome b5 stimulates a step following the first electron transfer during cytochrome P450 6A1 turnover.
Ariel Ceferino Toloza - One of the best experts on this subject based on the ideXlab platform.
-
Insecticide resistance of House Fly, Musca domestica (L.) from Argentina
Parasitology Research, 2009Co-Authors: Gonzalo Roca Acevedo, Miguel Zapater, Ariel Ceferino TolozaAbstract:The status of resistance to cyromazine, 2,2-dichlorovinyl dimethyl phosphate (DDVP), and permethrin relative to field populations of the House Fly, Musca domestica L. from Argentinean poultry farms was studied. All the three studied populations (SV, Q, and C) showed resistant ratios (RRs) to cyromazine of 3.9, 10.98, and 62.5, respectively. We observed high levels of resistance toward the organophosphate DDVP and permethrin. The RRs to DDVP ranged from 45.4 to 62.5. No significant differences were found among the studied populations. All the House Fly populations were permethrin-resistant, in comparison with the susceptible strain. Two of the analyzed populations (SV and Q) differed significantly in toxicity to the population C. This is the first evidence that House flies from Argentina showed a multi-resistance pattern. The implementation of an insecticide monitoring program on poultry farms of Argentina is needed to prevent field control failures. Furthermore, integrated control strategies are needed to delay detrimental development of insecticide resistance.