Multiple recombination events between two cytochrome P450 loci contribute to global pyrethroid resistance in Helicoverpa armigera

The cotton bollworm, Helicoverpa armigera (Hübner) is one of the most serious insect pest species to evolve resistance against many insecticides from different chemical classes. This species has evolved resistance to the pyrethroid insecticides across its native range and is becoming a truly global pest after establishing in South America and having been recently recorded in North America. A chimeric cytochrome P450 gene, CYP337B3, has been identified as a resistance mechanism for resistance to fenvalerate and cypermethrin. Here we show that this resistance mechanism is common around the world with at least eight different alleles. It is present in South America and has probably introgressed into its closely related native sibling species, Helicoverpa zea. The different alleles of CYP337B3 are likely to have arisen independently in different geographic locations from selection on existing diversity. The alleles found in Brazil are those most commonly found in Asia, suggesting a potential origin for the incursion of H. armigera into the Americas.Additional co-authors: Mary E A Whitehouse, Pierre Jean Silvie, Sharon Downes, Lori Nemec, David G. Hecke

Multiple recombination events between two cytochrome P450 loci contribute to global pyrethroid resistance in Helicoverpa armigera

The cotton bollworm, Helicoverpa armigera (Hübner) is one of the most serious insect pest species to evolve resistance against many insecticides from different chemical classes. This species has evolved resistance to the pyrethroid insecticides across its native range and is becoming a truly global pest after establishing in South America and having been recently recorded in North America. A chimeric cytochrome P450 gene, CYP337B3, has been identified as a resistance mechanism for resistance to fenvalerate and cypermethrin. Here we show that this resistance mechanism is common around the world with at least eight different alleles. It is present in South America and has probably introgressed into its closely related native sibling species, Helicoverpa zea. The different alleles of CYP337B3 are likely to have arisen independently in different geographic locations from selection on existing diversity. The alleles found in Brazil are those most commonly found in Asia, suggesting a potential origin for the incursion of H. armigera into the Americas

Multiple recombination events between two cytochrome P450 loci contribute to global pyrethroid resistance in Helicoverpa armigera

The cotton bollworm, Helicoverpa armigera (Hübner) is one of the most serious insect pest species to evolve resistance against many insecticides from different chemical classes. This species has evolved resistance to the pyrethroid insecticides across its native range and is becoming a truly global pest after establishing in South America and having been recently recorded in North America. A chimeric cytochrome P450 gene, CYP337B3, has been identified as a resistance mechanism for resistance to fenvalerate and cypermethrin. Here we show that this resistance mechanism is common around the world with at least eight different alleles. It is present in South America and has probably introgressed into its closely related native sibling species, Helicoverpa zea. The different alleles of CYP337B3 are likely to have arisen independently in different geographic locations from selection on existing diversity. The alleles found in Brazil are those most commonly found in Asia, suggesting a potential origin for the incursion of H. armigera into the Americas.Financial support in Australia (to TKW) was provided by the Commonwealth Science and Industry Research Organisation, Land and Water, Health and Biosecurity, Agriculture. In Germany financial support (to DGH) was provided by the Max-Planck-Gesellschaft. NJ was supported by a grant from the Deutsche Forschungsgemeinschaf (DFG, Germany; JO 855/1-1)

Multiple recombination events between two cytochrome P450 loci contribute to global pyrethroid resistance in Helicoverpa armigera

The cotton bollworm, Helicoverpa armigera (Hubner) is one of the most serious insect pest species to evolve resistance against many insecticides from different chemical classes. This species has evolved resistance to the pyrethroid insecticides across its native range and is becoming a truly global pest after establishing in South America and having been recently recorded in North America. A chimeric cytochrome P450 gene, CYP337B3, has been identified as a resistance mechanism for resistance to fenvalerate and cypermethrin. Here we show that this resistance mechanism is common around the world with at least eight different alleles. It is present in South America and has probably introgressed into its closely related native sibling species, Helicoverpa zea. The different alleles of CYP337B3 are likely to have arisen independently in different geographic locations from selection on existing diversity. The alleles found in Brazil are those most commonly found in Asia, suggesting a potential origin for the incursion of H. armigera into the Americas

Rhodium-Catalyzed Oxidative Cyclization of Arylphosphonic Acid Monoethyl Esters with Alkenes: Efficient Synthesis of Benzoxaphosphole 1‑Oxides

Rhodium-catalyzed tandem oxidative alkenylation and an intramolecular <i>oxy</i>-Michael reaction were developed using arylphosphonic acid monoethyl esters and alkenes under aerobic conditions, which produced benzoxaphosphole 1-oxides in good to excellent yields

Tailorable Degradation of pH-Responsive All Polyether Micelles via Copolymerisation with Varying Acetal Groups

Smart drug delivery in a site-specific and time-controlled manner is critical for reducing the side effects of the drug while maximizing the therapeutic efficacy. Herein, we describe an efficient approach to control the degradation kinetics of polyether micelles under acidic conditions using random copolymers of functional epoxide monomers bearing different acetal groups. The amphiphilic block copolymers, poly(ethylene glycol)-block-poly(ethoxyethyl glycidyl ether-co-tetrahydropyranyl glycidyl ether)s (PEG-b-P(EEGE-co-TGE))s, are synthesized by the anionic ring-opening polymerisation of the pH-responsive novel epoxide monomers ethoxyethyl glycidyl ether (EEGE) and tetrahydropyranyl glycidyl ether (TGE) in varying ratios. The random block copolymers are carefully characterized by 1H NMR, GPC, and DSC and the copolymerisation kinetics are evaluated using in situ 1H NMR analysis. The critical micelle concentrations, loading efficiencies, and size distributions of the copolymer micelles show a saturation point over a critical TGE ratio. Interestingly, the degradation and subsequent release kinetics of the micelles under acidic conditions are remarkably different when the composition of the acetal groups is varied. The superior biocompatibility coupled with the highly tailorable release kinetics is anticipated to lead to a versatile platform for smart drug delivery systems

Synthesis of <i>N</i>‑Imidoyl and <i>N</i>‑Oxoimidoyl Sulfoximines from 1‑Alkynes, <i>N</i>‑Sulfonyl Azides, and Sulfoximines

<i>N</i>-Imidoylation of sulfoximines is developed from a Cu-catalyzed three-component reaction from 1-alkynes, <i>N</i>-sulfonyl azides, and sulfoximines in THF at room temperature under air. In addition, <i>N</i>-oxoimidoylation of sulfoximines is accessed from a Cu-catalyzed three-component reaction from 1-alkynes, <i>N</i>-sulfonyl azides, and sulfoximines in THF at room temperature followed by a Cu-catalyzed oxidative reaction at 50 °C under air, producing <i>N</i>-oxoimidoyl sulfoximines

Gene selection tool (GST): A R-based tool for genetic disorders based on the sliding-window proportion test using whole-exome sequencing data

<div><p>Whole-exome sequencing (WES) can identify causative mutations in hereditary diseases. However, WES data might have a large candidate variant list, including false positives. Moreover, in families, it is more difficult to select disease-associated variants because many variants are shared among members. To reduce false positives and extract accurate candidates, we used a multilocus variant instead of a single-locus variant (SNV). We set up a specific window to analyze the multilocus variant and devised a sliding-window approach to observe all variants. We developed the gene selection tool (GST) based on proportion tests for linkage analysis using WES data. This tool is R program coded and has high sensitivity. We tested our code to find the gene for hereditary spastic paraplegia using SNVs from a specific family and identified the gene known to cause the disease in a significant gene list. The list identified other genes that might be associated with the disease.</p></div

A list of significant genes deduced by GST analysis.

<p>A list of significant genes deduced by GST analysis.</p