Green apple aphid, Aphis pomi De Geer, and Aphis spiraecola Patch (both Hemiptera: Aphididae), are sympatric aphid species that are pests of apples (Malus spp.) and other crops. A. spiraecola has been shown to be significantly more tolerant to several insecticides compared with A. pomi. To establish the mechanisms contributing to this difference in insecticide response, clones of both species were collected from British Columbia, Canada, and Washington state. Dose-response bioassays were conducted to determine relative tolerances to the insecticides pirimicarb, dimethoate, and imidacloprid; these results have been reported previously. Samples of adult aphids from each clone were assayed for the activity of esterase enzymes often involved in the detoxification of insecticides. A. spiraecola had higher esterase activity compared with A. pomi; this was apparent for two model substrates, alpha-naphthyl acetate (alpha-NA) and alpha-naphthyl butyrate (alpha-NB). Aphid clones of both species collected from Washington had higher esterase activity than clones collected from British Columbia. Clones from both species and locations hydrolyzed alpha-NA to a greater extent than alpha-NB. Esterase activity measured with both substrates was significantly positively correlated with the relative response to pirimicarb and dimethoate; a significant positive correlation also was found for hydrolysis of alpha-NB and imidacloprid. The apparent involvement of esterases in the differential response of A. pomi and A. spiraecola to insecticides indicated that the choice of control chemicals for A. spiraecola should not involve chemistries that are metabolized predominantly by esterases.
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http://dx.doi.org/10.1603/ec09275 | DOI Listing |
Nat Microbiol
January 2025
Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada.
Bacterial genomes have regions known as defence islands that encode diverse systems to protect against phage infection. Although genetic elements that capture and store gene cassettes in Vibrio species, called integrons, are known to play an important role in bacterial adaptation, a role in phage defence had not been defined. Here we combine bioinformatic and molecular techniques to show that the chromosomal integron of Vibrio parahaemolyticus is a hotspot for anti-phage defence genes.
View Article and Find Full Text PDFMethods Enzymol
January 2025
Department of Neurobiology, Duke University School of Medicine, Durham, NC, United States; Department of Biomedical Engineering, Duke University, Durham, NC, United States. Electronic address:
RNAs are central mediators of genetic information flow and gene regulation that underlie diverse cell types and cell states across species. Thus, methods that can sense and respond to RNA profiles in living cells will have broad applications in biology and medicine. CellREADR - Cell access through RNA sensing by Endogenous ADAR (adenosine deaminase acting on RNA), is a programmable RNA sensor-actuator technology that couples the detection of a cell-defining RNA to the translation of an effector protein to monitor and manipulate the cell.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Nanjing University, School of Chemistry and Chemical Engineering, CHINA.
T cells play a pivotal role in the development of autoimmune diseases. To mitigate autoimmune inflammation without inducing global immunosuppression, it is crucial to selectively eliminate autoreactive T cell clones while preserving the normal T cell repertoire. In this study, we applied cellular proximity chemistry to develop a T-cell depletion method with clonal precision.
View Article and Find Full Text PDFInfect Prev Pract
March 2025
Norwegian National Advisory Unit on Detection of Antimicrobial Resistance, Department of Microbiology and Infection Control, University Hospital of North Norway, Tromsø, Norway.
Background: Nosocomial outbreaks with multidrug-resistant bacteria with a probable reservoir in hospital toilets and drainage systems have been increasingly reported.
Aim: To investigate an increase in bacteraemia with extended-spectrum β-lactamase (ESBL)-producing at our hospital in 2021; the epidemiology of the outbreak suggested an environmental source.
Methods: Available clinical isolates from patient with infection or rectal carriage from 2019 to 2022 were collected.
Anim Reprod
January 2025
Faculdade de Zootecnia e Engenharia de Alimentos - FZEA, Universidade de São Paulo - USP, Pirassununga, SP, Brasil.
Somatic cell nuclear transfer (SCNT), or cloning, is used to reprogram cells and generate genetically identical embryos and animals. However, the cloning process is inefficient, limiting its application to producing valuable animals. In swine, cloning is mainly utilized to produce genetically modified animals.
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