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Schöfer N, Ackermann J, Hoheneder J, Hofferberth J, Ruther J. Sublethal Effects of Four Insecticides Targeting Cholinergic Neurons on Partner and Host Finding in the Parasitic Wasp Nasonia vitripennis. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2023; 42:2400-2411. [PMID: 37477474 DOI: 10.1002/etc.5721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 07/03/2023] [Accepted: 07/18/2023] [Indexed: 07/22/2023]
Abstract
Lethal and sublethal effects of pesticides on nontarget organisms are one of the causes of the current decline of many insect species. However, research in the past decades has focused primarily on pollinators, although other beneficial nontarget organisms such as parasitic wasps may also be affected. We studied the sublethal effects of the four insecticides acetamiprid, dimethoate, flupyradifurone, and sulfoxaflor on pheromone-mediated sexual communication and olfactory host finding of the parasitic wasp Nasonia vitripennis. All agents target cholinergic neurons, which are involved in the processing of chemical information by insects. We applied insecticide doses topically and tested the response of treated wasps to sex pheromones and host-associated chemical cues. In addition, we investigated the mating rate of insecticide-treated wasps. The pheromone response of females surviving insecticide treatment was disrupted by acetamiprid (≥0.63 ng), dimethoate (≥0.105 ng), and flupyradifurone (≥21 ng), whereas sulfoxaflor had no significant effects at the tested doses. Olfactory host finding was affected by all insecticides (acetamiprid ≥1.05 ng, dimethoate ≥0.105 ng, flupyradifurone ≥5.25 ng, sulfoxaflor ≥0.52 ng). Remarkably, females treated with ≥0.21 ng dimethoate even avoided host odor. The mating rate of treated N. vitripennis couples was decreased by acetamiprid (6.3 ng), flupyradifurone (≥2.63 ng), and sulfoxaflor (2.63 ng), whereas dimethoate showed only minor effects. Finally, we determined the amount of artificial nectar consumed by N. vitripennis females within 48 h. Considering this amount (∼2 µL) and the maximum concentrations of the insecticides reported in nectar, tested doses can be considered field-realistic. Our results suggest that exposure of parasitic wasps to field-realistic doses of insecticides targeting the cholinergic system reduces their effectiveness as natural enemies by impairing the olfactory sense. Environ Toxicol Chem 2023;42:2400-2411. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
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Affiliation(s)
- Nils Schöfer
- Institute of Zoology, University of Regensburg, Regensburg, Germany
| | - Julian Ackermann
- Institute of Zoology, University of Regensburg, Regensburg, Germany
| | - Julian Hoheneder
- Institute of Zoology, University of Regensburg, Regensburg, Germany
| | | | - Joachim Ruther
- Institute of Zoology, University of Regensburg, Regensburg, Germany
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2
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Cowled MS, Li H, Gilchrist CLM, Lacey E, Chooi YH, Piggott AM. Stereodivergent Hydroxylation of Berkeleylactones by Penicillium turbatum. JOURNAL OF NATURAL PRODUCTS 2023; 86:541-549. [PMID: 36524608 DOI: 10.1021/acs.jnatprod.2c00946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Penicillium turbatum has previously been reported to produce A26771B, a 16-membered macrocyclic polyketide with activity against Gram-positive bacteria, mycoplasma, and fungi, as well as the structurally related compounds berkeleylactone E and berkeleylactones I-O. In this work, large-scale cultivation of P. turbatum NRRL 5630 on rice yielded seven new berkeleylactone analogues, berkeleylactone E methyl ester, 14-epi-berkeleylactone F, berkeleylactones P-R, 12-epi-berkeleylactone Q, and 13-epi-berkeleylactone R, and six previously reported analogues, A26771B and berkeleylactones E-G and J-K. The structures of the berkeleylactones were elucidated by detailed analysis of spectroscopic data, molecular modeling, and comparison with literature values. Interestingly, six of the berkeleylactone analogues were isolated as pairs of hydroxy epimers, highlighting how Nature can exploit stereodivergence in biosynthetic pathways to increase chemical diversity. The genome of P. turbatum was sequenced, and a putative gene cluster (bekl) responsible for the biosynthesis of the berkeleylactones was identified. The new berkeleylactone analogues exhibited no significant biological activity against a panel of bacteria, fungi, the parasite Giardia duodenalis, or NS-1 murine myeloma cells, suggesting a hitherto undiscovered biological role.
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Affiliation(s)
- Michael S Cowled
- School of Natural Sciences, Macquarie University, Sydney, NSW 2109, Australia
| | - Hang Li
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, Guangdong 510006, People's Republic of China
- School of Molecular Sciences, The University of Western Australia, Perth, WA 6009, Australia
| | - Cameron L M Gilchrist
- School of Molecular Sciences, The University of Western Australia, Perth, WA 6009, Australia
| | - Ernest Lacey
- School of Natural Sciences, Macquarie University, Sydney, NSW 2109, Australia
- Microbial Screening Technologies Pty. Ltd., Smithfield, NSW 2164, Australia
| | - Yit-Heng Chooi
- School of Molecular Sciences, The University of Western Australia, Perth, WA 6009, Australia
| | - Andrew M Piggott
- School of Natural Sciences, Macquarie University, Sydney, NSW 2109, Australia
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3
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Kurtanovic A, Hofferberth J, Ruther J. Male sex pheromone in the parasitoid wasp Nasonia longicornis: Chemical and behavioral analyses. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.1076398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
The use of sex pheromones for the attraction of potential mating partners is widespread in insects. Species-specificity of these chemical signals is essential, particularly in closely related species with overlapping habitats. In parasitoid wasps of the genus Nasonia, it is the males that produce sex pheromones in their rectal vesicles. The genus consists of four species: N. vitripennis (Nv), N. giraulti (Ng), N. oneida (No), and N. longicornis (Nl). The cosmopolitan species Nv is sympatric with Ng and No in eastern North America and with Nl in the west. Interspecific courtship is common in Nasonia although hybridization is prevented in most combinations by Wolbachia-mediated cytoplasmic incompatibility. The pheromone of Nv males differs from all Nasonia congeners by an additional component that is believed to ensure precopulatory isolation from the sympatric congeners. Detailed investigations on these interactions, however, exist only for the species combination Nv/Ng. Here, we report the results of chemical and behavioral investigations on the sex pheromone of Nl males. The pheromone consists of (4R,5S)-5-hydroxy-4-decanolide (RS) and 4-methylquinazoline (MQ) as a minor component which are produced only after eclosion. Pheromone titers peaked 2 days after eclosion and remained constant on day three. The pheromone is deposited by abdomen dipping which males increasingly exhibited after mating or brief contact with a female. The presence of hosts containing females about to emerge did not increase marking behavior. Site fidelity of males at their own pheromone markings is mediated by MQ. Both natural and synthetic pheromone attracted virgin but not mated females and both RS and MQ are required for female attraction. Females collected during emergence from the host responded likewise to the pheromone and 84% of them produced mixed-sex offspring showing that most of them emerge unmated. Nl females preferred pheromone extract from conspecific males to extract from Nv males, and the addition of the Nv-specific component (4R,5R)-5-hydroxy-4-decanolide (RR) to the Nl pheromone made them unresponsive. The present study demonstrates that Nl uses the male sex pheromone in a similar way as previously shown for Nv and Ng. Furthermore, it shows that Nl females use the Nv-specific pheromone component RR to avoid costly sexual interactions with Nv males in regions of sympatry.
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Cheng JQ, Tao YM, Li J, Chen YZ, Hu HY. Characterization of male-biased fatty acid desaturase in the jewel wasp Nasonia vitripennis and its role in pheromone production. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART B, MOLECULAR AND DEVELOPMENTAL EVOLUTION 2022; 338:421-429. [PMID: 34995007 DOI: 10.1002/jez.b.23120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 12/06/2021] [Accepted: 12/19/2021] [Indexed: 06/14/2023]
Abstract
Linoleic acid is the material for biosynthesis of sex attracting and blocking (postmating) pheromones in Nasonia vitripennis, it is synthesized from oleic acid by a male-biased fatty acid desaturase (SCD5a). In this study, we developed a specific antibody and further characterized the expression patterns of SCD5a in males at different mating stages by western blot. SCD5a was mainly expressed in male heads rather than in abdomens. Along with the aging process (from Day 1 to Day 3), SCD5a increased significantly. Compared with virgin males, mated males showed higher levels of SCD5a. Likewise, abdomen dipping frequency, during which males release attracting pheromone, increased with age and mating. Moreover, real-time quantitative PCR revealed that genes responsible for the first three steps of attracting pheromone biosynthesis were more highly expressed in head than in abdomen, but the final gene for transformation of attracting pheromone was more highly expressed in abdomen than in head. These results suggest that linoleic acid for biosynthesis of attracting pheromones may also originate from the head rather than only synthesized at the rectal vesicles.
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Affiliation(s)
- Jian-Qiu Cheng
- School of Ecology and Environment, Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, Anhui Normal University, Wuhu, Anhui, China
| | - Yu-Mei Tao
- School of Ecology and Environment, Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, Anhui Normal University, Wuhu, Anhui, China
| | - Jing Li
- School of Ecology and Environment, Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, Anhui Normal University, Wuhu, Anhui, China
| | - Yong-Zhuo Chen
- School of Ecology and Environment, Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, Anhui Normal University, Wuhu, Anhui, China
| | - Hao-Yuan Hu
- School of Ecology and Environment, Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, Anhui Normal University, Wuhu, Anhui, China
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Liang D, Shu R, Jiang S, Yang L, Wang Y, Zhao Y, Cai Y, Xie R, Meng Y. Identification and functional analysis of carbonyl reductases related to tetrahydrobiopterin synthesis in the silkworm, Bombyx mori. INSECT MOLECULAR BIOLOGY 2022; 31:403-416. [PMID: 35184330 DOI: 10.1111/imb.12768] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 01/21/2022] [Accepted: 02/14/2022] [Indexed: 06/14/2023]
Abstract
The superfamily of short-chain dehydrogenases/reductases (SDRs) is crucial in biosynthetic and signalling pathways, in which the carbonyl reductases (CBRs) subfamily is important in the biosynthesis of tetrahydrobiopterin (BH4). BH4 is an essential coenzyme for animals, and its deficiency can lead to neurological diseases. There are few reports on CBRs involved in BH4 synthesis of silkworms, Bombyx mori. Here, we identified 67 SDR genes in B. mori (BmSDR) through whole genome survey for the first time. Based on bioinformatics analyses and KEGG verification, four BmCBRs that may be related to BH4 synthesis were further characterized and functionally analysed. The results showed these four genes were high expressed in the head and gonads of ah09 (a lem mutant with defective BH4 synthesis). Enzyme activity, BH4 content and the related gene expression levels after intracellular interference with BmCBR and the main catalytic enzymes sepiapterin reductase of B. mori (BmSpr) in the de novo pathway of BH4 showed BmCBR2 plays a role in the salvage pathway. BmCBR3 and BmCBR4 regulate BH4 synthesis through the alternative pathway. Among the four pathways of silkworm BH4 synthesis, the de novo pathway occupies the dominant position, followed by the alternative pathway and salvage pathway. According to the overexpression of BmCBR3 after interference with BmSpr, the BH4 content did not change significantly. It is speculated that BmCBR3 is located upstream of BmSpr. These results provide a theoretical basis for in-depth exploration of the role of BmSDR in B. mori and also provide clues for the research of other animal-related diseases.
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Affiliation(s)
- Dan Liang
- School of Life Sciences, Anhui Agricultural University, Hefei, China
- Anhui International Joint Research and Development Center of Sericulture Resources Utilization, Hefei, China
| | - Rui Shu
- School of Life Sciences, Anhui Agricultural University, Hefei, China
- Institute of Sericulture, Anhui Academy of Agricultural Sciences, Hefei, China
| | - Song Jiang
- School of Life Sciences, Anhui Agricultural University, Hefei, China
- Anhui International Joint Research and Development Center of Sericulture Resources Utilization, Hefei, China
| | - Liangli Yang
- School of Life Sciences, Anhui Agricultural University, Hefei, China
- Anhui International Joint Research and Development Center of Sericulture Resources Utilization, Hefei, China
| | - Ying Wang
- School of Life Sciences, Anhui Agricultural University, Hefei, China
| | - Yue Zhao
- School of Life Sciences, Anhui Agricultural University, Hefei, China
| | - Yangyang Cai
- School of Life Sciences, Anhui Agricultural University, Hefei, China
| | - Ruiping Xie
- School of Life Sciences, Anhui Agricultural University, Hefei, China
| | - Yan Meng
- School of Life Sciences, Anhui Agricultural University, Hefei, China
- Anhui International Joint Research and Development Center of Sericulture Resources Utilization, Hefei, China
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Prager L, Bruckmann A, Ruther J. De novo biosynthesis of fatty acids from α-D-glucose in parasitoid wasps of the Nasonia group. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2019; 115:103256. [PMID: 31655163 DOI: 10.1016/j.ibmb.2019.103256] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 10/18/2019] [Accepted: 10/18/2019] [Indexed: 06/10/2023]
Abstract
Fatty acids are indispensable primary metabolites for virtually any organism on earth and thus enzymatic machinery enabling de novo production of fatty acids from carbohydrates is highly conserved. A series of studies has questioned the ubiquity of lipogenesis in parasitoid wasps suggesting that the vast majority of species have lost the ability to synthesize fatty acids de novo. One such species is Nasonia vitripennis, which, like the congeneric species N. giraulti and N. longicornis, uses a fatty acid-derived male sex pheromone for sexual communication. Here we demonstrate by feeding fully 13C-labeled α-D-glucose and analyzing insect-derived fatty acid methyl esters and the male sex pheromone by coupled gas chromatography/mass spectrometry that both males and females of N. vitripennis as well as N. giraulti and N. longicornis are capable of synthesizing fatty acids de novo. We furthermore show by a proteomics approach that predicted fatty acid synthase, ATP-citrate synthase, and acetyl-CoA carboxylase, key enzymes of lipogenesis, are expressed in the male pheromone gland of N. vitripennis and N. giraulti. Labeling experiments with Urolepis rufipes, a closely related species producing a male sex pheromone independently of fatty acids via the mevalonate pathway, revealed that both sexes are likewise able to synthesize fatty acids de novo. We conclude that the parasitoid wasp species studied here, irrespective of the biosynthetic origin of their sex pheromones, are capable of responding flexibly to lipid shortage during their adult life by keeping enzymatic machinery for lipogenesis running.
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Affiliation(s)
- Lorena Prager
- University of Regensburg, Institute of Zoology, Universitätsstraße 31, 93053, Regensburg, Germany.
| | - Astrid Bruckmann
- University of Regensburg, Institute of Biochemistry Genetics and Microbiology, Universitätsstraße 31, 93053, Regensburg, Germany.
| | - Joachim Ruther
- University of Regensburg, Institute of Zoology, Universitätsstraße 31, 93053, Regensburg, Germany.
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7
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Mair MM, Ruther J. Chemical Ecology of the Parasitoid Wasp Genus Nasonia (Hymenoptera, Pteromalidae). Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00184] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
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8
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Semmelmann F, Kabeya N, Malcicka M, Bruckmann A, Broschwitz B, Straub K, Merkl R, Monroig O, Sterner R, Ruther J, Ellers J. Functional characterisation of two Δ12-desaturases demonstrates targeted production of linoleic acid as pheromone precursor in Nasonia. ACTA ACUST UNITED AC 2019; 222:jeb.201038. [PMID: 31019064 DOI: 10.1242/jeb.201038] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 04/18/2019] [Indexed: 01/08/2023]
Abstract
Insect pheromones are often derived from fatty acid metabolism. Fatty acid desaturases, enzymes introducing double bonds into fatty acids, are crucial for the biosynthesis of these chemical signals. Δ12-desaturases catalyse the biosynthesis of linoleic acid by introducing a second double bond into oleic acid, but have been identified in only a few animal species. Here, we report the functional characterisation of two Δ12-desaturases, Nvit_D12a and Nvit_D12b, from the parasitic wasp Nasonia vitripennis. We demonstrate that Nvit_D12a is expressed in the rectal vesicle of males where they produce a linoleic acid-derived sex pheromone to attract virgin females. 13C-labelling experiments with Urolepis rufipes, a closely related species belonging to the 'Nasonia group', revealed that females, but not males, are able to synthesise linoleic acid. U. rufipes males produce an isoprenoid sex pheromone in the same gland and do not depend on linoleic acid for pheromone production. This suggests that Δ12-desaturases are common in the 'Nasonia group', but acquired a specialised function in chemical communication of those species that use linoleic acid as a pheromone precursor. Phylogenetic analysis suggests that insect Δ12-desaturases have evolved repeatedly from Δ9-desaturases in different insect taxa. Hence, insects have developed a way to produce linoleic acid independent of the omega desaturase subfamily which harbours all of the eukaryotic Δ12-desaturases known so far.
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Affiliation(s)
- Florian Semmelmann
- Institute of Biophysics and Physical Biochemistry, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Naoki Kabeya
- Department of Aquatic Bioscience, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, 113-8657 Tokyo, Japan
| | - Miriama Malcicka
- Department of Ecological Sciences, Vrije Universiteit, Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
| | - Astrid Bruckmann
- Institute of Biochemistry, Genetics and Microbiology, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Bastian Broschwitz
- Institute of Zoology, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Kristina Straub
- Institute of Biophysics and Physical Biochemistry, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Rainer Merkl
- Institute of Biophysics and Physical Biochemistry, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Oscar Monroig
- Instituto de Acuicultura Torre de la Sal, Consejo Superior de Investigaciones Científicas (IATS-CSIC), Ribera de Cabanes 12595, Spain
| | - Reinhard Sterner
- Institute of Biophysics and Physical Biochemistry, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Joachim Ruther
- Institute of Zoology, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Jacintha Ellers
- Department of Ecological Sciences, Vrije Universiteit, Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
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Ruther J, Wittman T, Grimm C, Feichtner FS, Fleischmann S, Kiermaier J, King BH, Kremer W, Kalbitzer HR, Schulz S. Male Sex Pheromone of the Parasitoid Wasp Urolepis rufipes Demonstrates Biosynthetic Switch Between Fatty Acid and Isoprenoid Metabolism Within the Nasonia Group. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00026] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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10
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Mapping key amino acid residues for the epimerase efficiency and stereospecificity of the sex pheromone biosynthetic short-chain dehydrogenases/reductases of Nasonia. Sci Rep 2019; 9:330. [PMID: 30674966 PMCID: PMC6344473 DOI: 10.1038/s41598-018-37200-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 12/05/2018] [Indexed: 11/09/2022] Open
Abstract
Males of the parasitic wasp genus Nasonia use blends of chiral hydroxylactones as sex pheromones to attract conspecific females. Whereas all Nasonia species use a mixture of (4R,5S)-5-hydroxy-4-decanolide (RS) and 4-methylquinazoline (MQ) as sex pheromones, Nasonia vitripennis evolved (4R,5R)-5-hydroxy-4-decanolide (RR) as an extra sex pheromone component. We recently identified and functionally characterized three short-chain dehydrogenases/reductases (SDRs) NV10127, NV10128, and NV10129 that are capable of catalyzing the epimerization of RS to RR via (4R)-5-oxo-4-decanolide (ODL) as intermediate. Despite their very high sequence identities of 88-98%, these proteins differ drastically in their ability to epimerize RS to RR and in their stereoselectivity when reducing ODL to RR/RS. Here, in order to unravel the sequence differences underlying these varying functional properties of NV1027, NV10128 and NV10129, we created chimeras of the three enzymes and monitored their catalytic activities in vitro. The results show that a few amino acid changes at the C-termini and active sites of Nasonia vitripennis SDRs lead to substantially altered RS to RR epimerization and ODL-reduction activities. Thus, our study adds to the understanding of pheromone evolution by showing that subtle mutations in key biosynthetic enzymes can result in drastic effects on the composition of chemical signals.
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11
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Lenschow M, Cordel M, Pokorny T, Mair MM, Hofferberth J, Ruther J. The Post-mating Switch in the Pheromone Response of Nasonia Females Is Mediated by Dopamine and Can Be Reversed by Appetitive Learning. Front Behav Neurosci 2018; 12:14. [PMID: 29441003 PMCID: PMC5797616 DOI: 10.3389/fnbeh.2018.00014] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 01/17/2018] [Indexed: 02/03/2023] Open
Abstract
The olfactory sense is of crucial importance for animals, but their response to chemical stimuli is plastic and depends on their physiological state and prior experience. In many insect species, mating status influences the response to sex pheromones, but the underlying neuromodulatory mechanisms are poorly understood. After mating, females of the parasitic wasp Nasonia vitripennis are no longer attracted to the male sex pheromone. Here we show that this post-mating behavioral switch is mediated by dopamine (DA). Females fed a DA-receptor antagonist prior to mating maintained their attraction to the male pheromone after mating while virgin females injected with DA became unresponsive. However, the switch is reversible as mated females regained their pheromone preference after appetitive learning. Feeding mated N. vitripennis females with antagonists of either octopamine- (OA) or DA-receptors prevented relearning of the pheromone preference suggesting that both receptors are involved in appetitive learning. Moreover, DA injection into mated females was sufficient to mimic the oviposition reward during odor conditioning with the male pheromone. Our data indicate that DA plays a key role in the plastic pheromone response of N. vitripennis females and reveal some striking parallels between insects and mammals in the neuromodulatory mechanisms underlying olfactory plasticity.
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Affiliation(s)
- Maria Lenschow
- Institute of Zoology, University of Regensburg, Regensburg, Germany
| | - Michael Cordel
- Institute of Zoology, University of Regensburg, Regensburg, Germany
| | - Tamara Pokorny
- Institute of Zoology, University of Regensburg, Regensburg, Germany
| | - Magdalena M Mair
- Institute of Zoology, University of Regensburg, Regensburg, Germany
| | - John Hofferberth
- Department of Chemistry, Kenyon College, Gambier, OH, United States
| | - Joachim Ruther
- Institute of Zoology, University of Regensburg, Regensburg, Germany
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12
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Tappert L, Pokorny T, Hofferberth J, Ruther J. Sublethal doses of imidacloprid disrupt sexual communication and host finding in a parasitoid wasp. Sci Rep 2017; 7:42756. [PMID: 28198464 PMCID: PMC5309895 DOI: 10.1038/srep42756] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 01/12/2017] [Indexed: 11/12/2022] Open
Abstract
Neonicotinoids are widely used insecticides, but their use is subject of debate because of their detrimental effects on pollinators. Little is known about the effect of neonicotinoids on other beneficial insects such as parasitoid wasps, which serve as natural enemies and are crucial for ecosystem functioning. Here we show that sublethal doses of the neonicotinoid imidacloprid impair sexual communication and host finding in the parasitoid wasp Nasonia vitripennis. Depending on the dose, treated females were less responsive to the male sex pheromone or unable to use it as a cue at all. Courtship behaviour of treated couples was also impeded resulting in a reduction of mating rates by up to 80%. Moreover, treated females were no longer able to locate hosts by using olfactory cues. Olfaction is crucial for the reproductive success of parasitoid wasps. Hence, sublethal doses of neonicotinoids might compromise the function of parasitoid wasps as natural enemies with potentially dire consequences for ecosystem services.
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Affiliation(s)
- Lars Tappert
- Institute of Zoology, University of Regensburg, 93053 Regensburg, Germany
| | - Tamara Pokorny
- Institute of Zoology, University of Regensburg, 93053 Regensburg, Germany
| | | | - Joachim Ruther
- Institute of Zoology, University of Regensburg, 93053 Regensburg, Germany
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