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  1. Article ; Online: Functional orthologs of honeybee CYP6AQ1 in stingless bees degrade the butenolide insecticide flupyradifurone.

    Xiao, Xingzhi / Haas, Julian / Nauen, Ralf

    Ecotoxicology and environmental safety

    2023  Volume 268, Page(s) 115719

    Abstract: Flupyradifurone (FPF), a novel butenolide insecticide binding to nicotinic acetylcholine receptors (nAChRs), has been shown to be less acutely toxic to western honey bees (Apis mellifera) than other insecticides such as neonicotinoids sharing the same ... ...

    Abstract Flupyradifurone (FPF), a novel butenolide insecticide binding to nicotinic acetylcholine receptors (nAChRs), has been shown to be less acutely toxic to western honey bees (Apis mellifera) than other insecticides such as neonicotinoids sharing the same target-site. A previous study revealed that this is due to enhanced oxidative metabolism of FPF, mediated by three cytochrome P450 monooxygenases (P450s), including CYP6AQ1. Therefore, we followed a toxicogenomics approach and investigated the potential role of functional CYP6AQ1 orthologs in FPF metabolism from eight different bee species, including stingless bees (Tribe: Meliponini). We conducted a phylogenetic analysis on four stingless bee species, including Frieseomelitta varia, Heterotrigona itama, Melipona quadrifasciata and Tetragonula carbonaria to identify CYP6AQ1-like functional orthologs. Three non-Meliponini, but tropical bee species, i.e., Ammobates syriacus, Euglossa dilemma and Megalopta genalis were analyzed as well. We identified candidate P450s in all (neo)tropical species with greater than 61% and 67% predicted protein sequence identities when compared to A. mellifera CYP6AQ1 and Bombus terrestris CYP6AQ26, respectively. Heterologous expression in High Five insect cells of these functional orthologs revealed a common coumarin substrate profile and a preference for the O-debenzylation of bulkier substrates. Competition assays using the fluorescent probe substrate 7-benzyloxymethoxy-4-trifluoromethylcoumarin (BOMFC) with these enzymes indicated inhibition of BOMFC metabolism by increasing concentrations of FPF. Furthermore, UPLC-MS/MS analysis revealed the capacity of all CYP6AQ1-like orthologs to metabolize FPF by hydroxylation in vitro at various levels, indicating a conserved FPF detoxification potential in different (neo)tropical bee species including Meliponini. This research, employing a toxicogenomics approach, provides important insights into the potential of stingless and other tropical bee species to detoxify FPF, and highlights the significance of investigating the detoxification mechanisms of insecticides in non-Apis bee species by molecular tools to inform risk assessment and conservation efforts.
    MeSH term(s) Animals ; Bees/genetics ; Bees/metabolism ; Chromatography, Liquid ; Insecticides/metabolism ; Phylogeny ; Tandem Mass Spectrometry
    Chemical Substances butenolide (8KXK25H388) ; flupyradifurone (8H7JT159D0) ; Insecticides
    Language English
    Publishing date 2023-11-21
    Publishing country Netherlands
    Document type Journal Article
    ZDB-ID 436536-7
    ISSN 1090-2414 ; 0147-6513
    ISSN (online) 1090-2414
    ISSN 0147-6513
    DOI 10.1016/j.ecoenv.2023.115719
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Pesticide risk assessment at the molecular level using honey bee cytochrome P450 enzymes: A complementary approach.

    Haas, Julian / Nauen, Ralf

    Environment international

    2021  Volume 147, Page(s) 106372

    Abstract: Honey bee (Apis mellifera) first-tier pesticide risk assessment is largely based on standardized laboratory toxicity bioassays after both acute and chronic exposure. Recent research on honey bee cytochrome P450 monooxygenases (P450s) uncovered CYP9Q3 as ... ...

    Abstract Honey bee (Apis mellifera) first-tier pesticide risk assessment is largely based on standardized laboratory toxicity bioassays after both acute and chronic exposure. Recent research on honey bee cytochrome P450 monooxygenases (P450s) uncovered CYP9Q3 as the molecular determinant mediating neonicotinoid insecticide selectivity and explaining why certain neonicotinoids such as thiacloprid show > 1000-fold lower acute toxicity than others (e.g. imidacloprid). Here this knowledge is leveraged for mechanistic risk assessment at the molecular level using a fluorescence-based high-throughput in vitro assay, predicting the interaction of diverse pesticidal chemotypes, including azole fungicides, with recombinantly expressed honey bee CYP9Q enzymes, known to metabolize thiacloprid, acetamiprid and tau-fluvalinate. Some azole fungicides were shown to be synergistic in combination with certain insecticides, including neonicotinoids and pyrethroids, whereas others such as prothioconazole were not. We demonstrate that biochemical CYP9Q2/CYP9Q3 inhibition data of azoles revealed a striking correlation with their synergistic potential at the organismal level, and even allow to explain combined toxicity effects observed for tank mixtures under field conditions. Our novel toxicogenomics-based approach is designed to complement existing methods for pesticide risk assessment with unprecedented screening capacity, by utilizing honey bee P450 enzymes known to confer pesticide selectivity, in order to biochemically address issues of ecotoxicological concern.
    MeSH term(s) Animals ; Bees ; Cytochrome P-450 Enzyme System/genetics ; Insecticides/toxicity ; Neonicotinoids/toxicity ; Pesticides/toxicity ; Risk Assessment
    Chemical Substances Insecticides ; Neonicotinoids ; Pesticides ; Cytochrome P-450 Enzyme System (9035-51-2)
    Language English
    Publishing date 2021-01-05
    Publishing country Netherlands
    Document type Journal Article
    ZDB-ID 554791-x
    ISSN 1873-6750 ; 0160-4120
    ISSN (online) 1873-6750
    ISSN 0160-4120
    DOI 10.1016/j.envint.2020.106372
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: The molecular determinants of pesticide sensitivity in bee pollinators.

    Bass, Chris / Hayward, Angela / Troczka, Bartlomiej J / Haas, Julian / Nauen, Ralf

    The Science of the total environment

    2024  Volume 915, Page(s) 170174

    Abstract: Bees carry out vital ecosystem services by pollinating both wild and economically important crop plants. However, while performing this function, bee pollinators may encounter potentially harmful xenobiotics in the environment such as pesticides ( ... ...

    Abstract Bees carry out vital ecosystem services by pollinating both wild and economically important crop plants. However, while performing this function, bee pollinators may encounter potentially harmful xenobiotics in the environment such as pesticides (fungicides, herbicides and insecticides). Understanding the key factors that influence the toxicological outcomes of bee exposure to these chemicals, in isolation or combination, is essential to safeguard their health and the ecosystem services they provide. In this regard, recent work using toxicogenomic and phylogenetic approaches has begun to identify, at the molecular level, key determinants of pesticide sensitivity in bee pollinators. These include detoxification systems that convert pesticides to less toxic forms and key residues in insecticide target-sites that underlie species-specific insecticide selectivity. Here we review this emerging body of research and summarise the state of knowledge of the molecular determinants of pesticide sensitivity in bee pollinators. We identify gaps in our knowledge for future research and examine how an understanding of the genetic basis of bee sensitivity to pesticides can be leveraged to, a) predict and avoid negative bee-pesticide interactions and facilitate the future development of pest-selective bee-safe insecticides, and b) inform traditional effect assessment approaches in bee pesticide risk assessment and address issues of ecotoxicological concern.
    MeSH term(s) Bees ; Animals ; Pesticides/analysis ; Insecticides/analysis ; Phylogeny ; Ecosystem ; Fungicides, Industrial/analysis
    Chemical Substances Pesticides ; Insecticides ; Fungicides, Industrial
    Language English
    Publishing date 2024-01-19
    Publishing country Netherlands
    Document type Journal Article ; Review
    ZDB-ID 121506-1
    ISSN 1879-1026 ; 0048-9697
    ISSN (online) 1879-1026
    ISSN 0048-9697
    DOI 10.1016/j.scitotenv.2024.170174
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article: Pesticide risk assessment at the molecular level using honey bee cytochrome P450 enzymes: A complementary approach

    Haas, Julian / Nauen, Ralf

    Environment international. 2021 Feb., v. 147

    2021  

    Abstract: Honey bee (Apis mellifera) first-tier pesticide risk assessment is largely based on standardized laboratory toxicity bioassays after both acute and chronic exposure. Recent research on honey bee cytochrome P450 monooxygenases (P450s) uncovered CYP9Q3 as ... ...

    Abstract Honey bee (Apis mellifera) first-tier pesticide risk assessment is largely based on standardized laboratory toxicity bioassays after both acute and chronic exposure. Recent research on honey bee cytochrome P450 monooxygenases (P450s) uncovered CYP9Q3 as the molecular determinant mediating neonicotinoid insecticide selectivity and explaining why certain neonicotinoids such as thiacloprid show > 1000-fold lower acute toxicity than others (e.g. imidacloprid). Here this knowledge is leveraged for mechanistic risk assessment at the molecular level using a fluorescence-based high-throughput in vitro assay, predicting the interaction of diverse pesticidal chemotypes, including azole fungicides, with recombinantly expressed honey bee CYP9Q enzymes, known to metabolize thiacloprid, acetamiprid and tau-fluvalinate. Some azole fungicides were shown to be synergistic in combination with certain insecticides, including neonicotinoids and pyrethroids, whereas others such as prothioconazole were not. We demonstrate that biochemical CYP9Q2/CYP9Q3 inhibition data of azoles revealed a striking correlation with their synergistic potential at the organismal level, and even allow to explain combined toxicity effects observed for tank mixtures under field conditions. Our novel toxicogenomics-based approach is designed to complement existing methods for pesticide risk assessment with unprecedented screening capacity, by utilizing honey bee P450 enzymes known to confer pesticide selectivity, in order to biochemically address issues of ecotoxicological concern.
    Keywords Apis mellifera ; acetamiprid ; acute toxicity ; azoles ; chemotypes ; chronic exposure ; cytochrome P-450 ; ecotoxicology ; environment ; fluvalinate ; honey bees ; imidacloprid ; pesticide selectivity ; pyrethrins ; risk assessment ; thiacloprid
    Language English
    Dates of publication 2021-02
    Publishing place Elsevier Ltd
    Document type Article
    Note NAL-AP-2-clean
    ZDB-ID 554791-x
    ISSN 1873-6750 ; 0160-4120
    ISSN (online) 1873-6750
    ISSN 0160-4120
    DOI 10.1016/j.envint.2020.106372
    Database NAL-Catalogue (AGRICOLA)

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  5. Article: A mechanism‐based approach unveils metabolic routes potentially mediating chlorantraniliprole synergism in honey bees, Apis mellifera L., by azole fungicides

    Haas, Julian / Glaubitz, Johannes / Koenig, Udo / Nauen, Ralf

    Pest management science. 2022 Mar., v. 78, no. 3

    2022  

    Abstract: BACKGROUND: Almond production in California is an intensively managed agroecosystem dependent on managed pollination by honey bees, Apis mellifera L. A recent laboratory study reported synergism in honey bees between chlorantraniliprole, a common diamide ...

    Abstract BACKGROUND: Almond production in California is an intensively managed agroecosystem dependent on managed pollination by honey bees, Apis mellifera L. A recent laboratory study reported synergism in honey bees between chlorantraniliprole, a common diamide insecticide used in almond orchards, and the fungicide propiconazole. Indeed, there is an emerging body of evidence that honey bee cytochrome P450 monooxygenases of the CYP9Q subfamily are involved in the detoxification of insecticides across a diverse range of chemical classes. The objective of the present study was to unveil the molecular background of the described synergism and to explore the potential role of CYP9Q enzymes in diamide detoxification. RESULTS: Our study confirmed the previously reported synergistic potential of propiconazole on chlorantraniliprole in acute contact toxicity bioassays, whereas no synergism was observed for flubendiamide. Fluorescence‐based biochemical assays revealed an interaction of chlorantraniliprole, but not flubendiamide, with functionally expressed CYP9Q2 and CYP9Q3. These findings were validated by an increased chlorantraniliprole tolerance of transgenic Drosophila lines expressing CYP9Q2/3, and an analytically confirmed oxidative metabolism of chlorantraniliprole by recombinantly expressed enzymes. Furthermore, we showed that several triazole fungicides used in almond orchards, including propiconazole, were strong nanomolar inhibitors of functionally expressed honey bee CYP9Q2 and CYP9Q3, whereas other fungicides such as iprodione and cyprodinil did not inhibit these enzymes. CONCLUSION: Honey bee CYP9Q enzymes are involved in chlorantraniliprole metabolism and inhibited by triazole fungicides possibly leading to synergism in acute contact toxicity bioassays. Our mechanistic approach has the potential to inform tier I honey bee pesticide risk assessment.
    Keywords Apis mellifera ; Drosophila ; aerobiosis ; agroecosystems ; almonds ; cyprodinil ; cytochrome P-450 ; flubendiamide ; genetically modified organisms ; honey ; honey bees ; insecticides ; iprodione ; propiconazole ; risk assessment ; synergism ; toxicity ; California
    Language English
    Dates of publication 2022-03
    Size p. 965-973.
    Publishing place John Wiley & Sons, Ltd.
    Document type Article
    Note JOURNAL ARTICLE
    ZDB-ID 2001705-4
    ISSN 1526-4998 ; 1526-498X
    ISSN (online) 1526-4998
    ISSN 1526-498X
    DOI 10.1002/ps.6706
    Database NAL-Catalogue (AGRICOLA)

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  6. Article ; Online: A mechanism-based approach unveils metabolic routes potentially mediating chlorantraniliprole synergism in honey bees, Apis mellifera L., by azole fungicides.

    Haas, Julian / Glaubitz, Johannes / Koenig, Udo / Nauen, Ralf

    Pest management science

    2021  Volume 78, Issue 3, Page(s) 965–973

    Abstract: Background: Almond production in California is an intensively managed agroecosystem dependent on managed pollination by honey bees, Apis mellifera L. A recent laboratory study reported synergism in honey bees between chlorantraniliprole, a common ... ...

    Abstract Background: Almond production in California is an intensively managed agroecosystem dependent on managed pollination by honey bees, Apis mellifera L. A recent laboratory study reported synergism in honey bees between chlorantraniliprole, a common diamide insecticide used in almond orchards, and the fungicide propiconazole. Indeed, there is an emerging body of evidence that honey bee cytochrome P450 monooxygenases of the CYP9Q subfamily are involved in the detoxification of insecticides across a diverse range of chemical classes. The objective of the present study was to unveil the molecular background of the described synergism and to explore the potential role of CYP9Q enzymes in diamide detoxification.
    Results: Our study confirmed the previously reported synergistic potential of propiconazole on chlorantraniliprole in acute contact toxicity bioassays, whereas no synergism was observed for flubendiamide. Fluorescence-based biochemical assays revealed an interaction of chlorantraniliprole, but not flubendiamide, with functionally expressed CYP9Q2 and CYP9Q3. These findings were validated by an increased chlorantraniliprole tolerance of transgenic Drosophila lines expressing CYP9Q2/3, and an analytically confirmed oxidative metabolism of chlorantraniliprole by recombinantly expressed enzymes. Furthermore, we showed that several triazole fungicides used in almond orchards, including propiconazole, were strong nanomolar inhibitors of functionally expressed honey bee CYP9Q2 and CYP9Q3, whereas other fungicides such as iprodione and cyprodinil did not inhibit these enzymes.
    Conclusion: Honey bee CYP9Q enzymes are involved in chlorantraniliprole metabolism and inhibited by triazole fungicides possibly leading to synergism in acute contact toxicity bioassays. Our mechanistic approach has the potential to inform tier I honey bee pesticide risk assessment.
    MeSH term(s) Animals ; Azoles ; Bees ; Fungicides, Industrial/toxicity ; Insecticides/toxicity ; ortho-Aminobenzoates/toxicity
    Chemical Substances Azoles ; Fungicides, Industrial ; Insecticides ; ortho-Aminobenzoates ; chlorantranilipole (622AK9DH9G)
    Language English
    Publishing date 2021-11-19
    Publishing country England
    Document type Journal Article
    ZDB-ID 2001705-4
    ISSN 1526-4998 ; 1526-498X
    ISSN (online) 1526-4998
    ISSN 1526-498X
    DOI 10.1002/ps.6706
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: Innovative Substrate-Integrated Hollow Waveguide Coupled Attenuated Total Reflection Sensors for Quantum Cascade Laser Based Infrared Spectroscopy in Harsh Environments.

    Teuber, Andrea / Stach, Robert / Haas, Julian / Mizaikoff, Boris

    Applied spectroscopy

    2021  Volume 76, Issue 1, Page(s) 132–140

    Abstract: An innovative mid-infrared spectroscopic sensor system based on quantum cascade lasers has been developed. The system combines the versatility of substrate-integrated hollow waveguides (IHWGs) with the robustness of attenuated total reflection (ATR) ... ...

    Abstract An innovative mid-infrared spectroscopic sensor system based on quantum cascade lasers has been developed. The system combines the versatility of substrate-integrated hollow waveguides (IHWGs) with the robustness of attenuated total reflection (ATR) crystals employed as internal reflection waveguides for evanescent field sensing. IHWGs are highly reflective metal structures that propagate infrared (IR) radiation and were used as light pipes for coupling radiation into the ATR waveguide. The combined IHWG-ATR device has been designed such that the utmost stability and robustness of the optical alignment were ensured. This novel assembly enables evanescent field absorption measurements at yet unprecedently harsh conditions, that is, high pressure and temperature. Combining these advantages, this innovative sensor assembly is perfectly suited for taking ATR spectroscopy into the field where the robustness of the assembly and optical alignment is essential.
    MeSH term(s) Infrared Rays ; Lasers, Semiconductor ; Spectrophotometry, Infrared
    Language English
    Publishing date 2021-12-10
    Publishing country United States
    Document type Journal Article
    ISSN 1943-3530
    ISSN (online) 1943-3530
    DOI 10.1177/00037028211064331
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: Expression profile of the entire detoxification gene inventory of the western honeybee, Apis mellifera across life stages.

    Maiwald, Frank / Haas, Julian / Hertlein, Gillian / Lueke, Bettina / Roesner, Janin / Nauen, Ralf

    Pesticide biochemistry and physiology

    2023  Volume 192, Page(s) 105410

    Abstract: The western honeybee, Apis mellifera, is a managed pollinator of many crops and potentially exposed to a wide range of foreign compounds, including pesticides throughout its life cycle. Honeybees as well as other insects recruit molecular defense ... ...

    Abstract The western honeybee, Apis mellifera, is a managed pollinator of many crops and potentially exposed to a wide range of foreign compounds, including pesticides throughout its life cycle. Honeybees as well as other insects recruit molecular defense mechanisms to facilitate the detoxification of xenobiotic compounds. The inventory of detoxification genes (DETOXome) is comprised of five protein superfamilies: cytochrome P450 monooxygenases (P450), carboxylesterases, glutathione S-transferases (GST), UDP-glycosyl transferases (UGT) and ATP-binding cassette (ABC) transporters. Here we characterized the gene expression profile of the entire honeybee DETOXome by analyzing 47 transcriptomes across the honeybee life cycle, including different larval instars, pupae, and adults. All life stages were well separated by principal component analysis, and K-means clustering revealed distinct temporal patterns of gene expression. Indeed, >50% of the honeybee detoxification gene inventory is found in one cluster and follows strikingly similar expression profiles, i.e., increased expression during larval development, followed by a sharp decline after pupation and a steep increase again in adults. This cluster includes 29 P450 genes dominated by CYP3 and CYP4 clan members, 15 ABC transporter genes mostly belonging to the ABCC subfamily and 13 carboxylesterase genes including almost all members involved in dietary/detox and hormone/semiochemical processing. RT-qPCR analysis of selected detoxification genes from all families revealed high expression levels in various tissues, especially Malpighian tubules, fatbody and midgut, supporting the view that these tissues are essential for metabolic clearance of environmental toxins and pollutants in honeybees. Our study is meant to spark further research on the molecular basis of detoxification in this critical pollinator to better understand and evaluate negative impacts from potentially toxic substances. Additionally, the entire gene set of 47 transcriptomes collected and analyzed provides a valuable resource for future honeybee research across different disciplines.
    MeSH term(s) Bees/genetics ; Animals ; Pesticides ; Insecta ; Cytochrome P-450 Enzyme System/genetics ; Cytochrome P-450 Enzyme System/metabolism ; Carboxylic Ester Hydrolases ; Transferases
    Chemical Substances Pesticides ; Cytochrome P-450 Enzyme System (9035-51-2) ; Carboxylic Ester Hydrolases (EC 3.1.1.-) ; Transferases (EC 2.-)
    Language English
    Publishing date 2023-03-28
    Publishing country United States
    Document type Journal Article
    ZDB-ID 184819-7
    ISSN 1095-9939 ; 0048-3583 ; 0048-3575
    ISSN (online) 1095-9939
    ISSN 0048-3583 ; 0048-3575
    DOI 10.1016/j.pestbp.2023.105410
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Book ; Online: LoRe

    Haas, Julian / Mogk, Ragnar / Yanakieva, Elena / Bieniusa, Annette / Mezini, Mira

    A Programming Model for Verifiably Safe Local-First Software

    2023  

    Abstract: Local-first software manages and processes private data locally while still enabling collaboration between multiple parties connected via partially unreliable networks. Such software typically involves interactions with users and the execution ... ...

    Abstract Local-first software manages and processes private data locally while still enabling collaboration between multiple parties connected via partially unreliable networks. Such software typically involves interactions with users and the execution environment (the outside world). The unpredictability of such interactions paired with their decentralized nature make reasoning about the correctness of local-first software a challenging endeavor. Yet, existing solutions to develop local-first software do not provide support for automated safety guarantees and instead expect developers to reason about concurrent interactions in an environment with unreliable network conditions. We propose LoRe, a programming model and compiler that automatically verifies developer-supplied safety properties for local-first applications. LoRe combines the declarative data flow of reactive programming with static analysis and verification techniques to precisely determine concurrent interactions that violate safety invariants and to selectively employ strong consistency through coordination where required. We propose a formalized proof principle and demonstrate how to automate the process in a prototype implementation that outputs verified executable code. Our evaluation shows that LoRe simplifies the development of safe local-first software when compared to state-of-the-art approaches and that verification times are acceptable.

    Comment: This is the extended version of the work accepted at ECOOP 2023
    Keywords Computer Science - Programming Languages
    Subject code 004
    Publishing date 2023-04-14
    Publishing country us
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  10. Book ; Online ; Thesis: Bee pollinators and pesticides

    Haas, Julian [Verfasser] / Grundler, Florian [Akademischer Betreuer] / Döring, Thomas [Gutachter]

    a toxicogenomics approach to illuminate the basis for selectivity and synergism

    2022  

    Author's details Julian Christopher Haas ; Gutachter: Thomas Döring ; Betreuer: Florian Grundler
    Keywords Landwirtschaft, Veterinärmedizin ; Agriculture, Veterinary Science
    Subject code sg630
    Language English
    Publisher Universitäts- und Landesbibliothek Bonn
    Publishing place Bonn
    Document type Book ; Online ; Thesis
    Database Digital theses on the web

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