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Hafeez M, Li X, Ullah F, Zhang Z, Zhang J, Huang J, Khan MM, Chen L, Ren X, Zhou S, Fernández-Grandon GM, Zalucki MP, Lu Y. Behavioral and Physiological Plasticity Provides Insights into Molecular Based Adaptation Mechanism to Strain Shift in Spodoptera frugiperda. Int J Mol Sci 2021; 22:10284. [PMID: 34638623 PMCID: PMC8508907 DOI: 10.3390/ijms221910284] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 09/19/2021] [Accepted: 09/21/2021] [Indexed: 12/20/2022] Open
Abstract
How herbivorous insects adapt to host plants is a key question in ecological and evolutionary biology. The fall armyworm, (FAW) Spodoptera frugiperda (J.E. Smith), although polyphagous and a major pest on various crops, has been reported to have a rice and corn (maize) feeding strain in its native range in the Americas. The species is highly invasive and has recently established in China. We compared behavioral changes in larvae and adults of a corn population (Corn) when selected on rice (Rice) and the molecular basis of these adaptational changes in midgut and antennae based on a comparative transcriptome analysis. Larvae of S. frugiperda reared on rice plants continuously for 20 generations exhibited strong feeding preference for with higher larval performance and pupal weight on rice than on maize plants. Similarly, females from the rice selected population laid significantly more eggs on rice as compared to females from maize population. The most highly expressed DEGs were shown in the midgut of Rice vs. Corn. A total of 6430 DEGs were identified between the populations mostly in genes related to digestion and detoxification. These results suggest that potential adaptations for feeding on rice crops, may contribute to the current rapid spread of fall armyworm on rice crops in China and potentially elsewhere. Consistently, highly expressed DEGs were also shown in antennae; a total of 5125 differentially expressed genes (DEGs) s were identified related to the expansions of major chemosensory genes family in Rice compared to the Corn feeding population. These results not only provide valuable insight into the molecular mechanisms in host plants adaptation of S. frugiperda but may provide new gene targets for the management of this pest.
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Affiliation(s)
- Muhammad Hafeez
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China; (M.H.); (X.L.); (Z.Z.); (J.Z.); (J.H.); (L.C.); (X.R.); (S.Z.)
- State Key Laboratory of Rice Biology, Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China
| | - Xiaowei Li
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China; (M.H.); (X.L.); (Z.Z.); (J.Z.); (J.H.); (L.C.); (X.R.); (S.Z.)
| | - Farman Ullah
- Department of Entomology, College of Plant Protection, China Agricultural University, Beijing 100193, China;
| | - Zhijun Zhang
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China; (M.H.); (X.L.); (Z.Z.); (J.Z.); (J.H.); (L.C.); (X.R.); (S.Z.)
| | - Jinming Zhang
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China; (M.H.); (X.L.); (Z.Z.); (J.Z.); (J.H.); (L.C.); (X.R.); (S.Z.)
| | - Jun Huang
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China; (M.H.); (X.L.); (Z.Z.); (J.Z.); (J.H.); (L.C.); (X.R.); (S.Z.)
| | - Muhammad Musa Khan
- Key Laboratory of Bio-Pesticide Innovation and Application, South China Agricultural University, Guangzhou 510642, China;
| | - Limin Chen
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China; (M.H.); (X.L.); (Z.Z.); (J.Z.); (J.H.); (L.C.); (X.R.); (S.Z.)
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Key Lab of Biopesticide and Chemical Biology, Ministry of Education & Fujian Province Key Laboratory of Insect Ecology, College of Plant Protection, Fujian Agriculture and Forest University, Fuzhou 350002, China
| | - Xiaoyun Ren
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China; (M.H.); (X.L.); (Z.Z.); (J.Z.); (J.H.); (L.C.); (X.R.); (S.Z.)
| | - Shuxing Zhou
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China; (M.H.); (X.L.); (Z.Z.); (J.Z.); (J.H.); (L.C.); (X.R.); (S.Z.)
| | | | - Myron P. Zalucki
- School of Biological Sciences, University of Queensland, Brisbane, QLD 4072, Australia;
| | - Yaobin Lu
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China; (M.H.); (X.L.); (Z.Z.); (J.Z.); (J.H.); (L.C.); (X.R.); (S.Z.)
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Gimenez S, Seninet I, Orsucci M, Audiot P, Nègre N, Nam K, Streiff R, d'Alençon E. Integrated miRNA and transcriptome profiling to explore the molecular determinism of convergent adaptation to corn in two lepidopteran pests of agriculture. BMC Genomics 2021; 22:606. [PMID: 34372780 PMCID: PMC8351448 DOI: 10.1186/s12864-021-07905-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 07/22/2021] [Indexed: 11/11/2022] Open
Abstract
Background The degree to which adaptation to same environment is determined by similar molecular mechanisms, is a topic of broad interest in evolutionary biology, as an indicator of evolutionary predictability. We wished to address if adaptation to the same host plant in phytophagous insects involved related gene expression patterns. We compared sRNA-Seq and RNA-Seq data between two pairs of taxa of Ostrinia and Spodoptera frugiperda sharing maize as host-plant. For the latter, we had previously carried out a reciprocal transplant experiment by feeding of the larvae of the Corn strain (Sf-C) and the Rice strain (Sf-R) on corn versus rice and characterized the mRNA and miRNA responses. Results First, we predicted the genes encoding miRNA in Ostrinia nubilalis (On) and O. scapulalis (Os). Respectively 67 and 65 known miRNA genes, as well as 196 and 190 novel ones were predicted with Os genome using sncRNAs extracted from whole larvae feeding on corn or mugwort. In On, a read counts analysis showed that 37 (55.22%) known miRNAs and 19 (9.84%) novel miRNAs were differentially expressed (DE) on mugwort compared to corn (in Os, 25 known miRs (38.46%) and 8 novel ones (4.34%)). Between species on corn, 8 (12.5%) known miRNAs and 8 (6.83%) novel ones were DE while only one novel miRNA showed expression variation between species on mugwort. Gene target prediction led to the identification of 2953 unique target genes in On and 2719 in Os, among which 11.6% (344) were DE when comparing species on corn. 1.8% (54) of On miR targets showed expression variation upon a change of host-plant. We found molecular changes matching convergent phenotype, i.e., a set of nine miRNAs that are regulated either according to the host-plant both in On and Sf-C or between them on the same plant, corn. Among DE miR target genes between taxa, 13.7% shared exactly the same annotation between the two pairs of taxa and had function related to insect host-plant interaction. Conclusion There is some similarity in underlying genetic mechanisms of convergent evolution of two distant Lepidopteran species having adopted corn in their host range, highlighting possible adaptation genes. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-07905-7.
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Affiliation(s)
| | | | - Marion Orsucci
- DGIMI, Univ Montpellier, INRAE, Montpellier, France.,CBGP, INRAE, CIRAD, IRD, Montpellier SupAgro, Univ Montpellier, Montpellier, France.,Department of Plant Biology, Uppsala BioCenter and Linnean Centre for Plant Biology, Swedish University of Agricultural Sciences, 75007, Uppsala, Sweden
| | - Philippe Audiot
- CBGP, INRAE, CIRAD, IRD, Montpellier SupAgro, Univ Montpellier, Montpellier, France
| | | | - Kiwoong Nam
- DGIMI, Univ Montpellier, INRAE, Montpellier, France
| | - Réjane Streiff
- CBGP, INRAE, CIRAD, IRD, Montpellier SupAgro, Univ Montpellier, Montpellier, France
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3
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Coates BS, Kozak GM, Seok Kim K, Sun J, Wang Y, Fleischer SJ, Dopman EB, Sappington TW. Influence of host plant, geography and pheromone strain on genomic differentiation in sympatric populations of Ostrinia nubilalis. Mol Ecol 2019; 28:4439-4452. [PMID: 31495004 DOI: 10.1111/mec.15234] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 07/19/2019] [Accepted: 08/05/2019] [Indexed: 12/26/2022]
Abstract
Patterns of mating for the European corn borer (Ostrinia nubilalis) moth depend in part on variation in sex-pheromone blend. The ratio of (E)-11- and (Z)-11-tetradecenyl acetate (E11- and Z11-14:OAc) in the pheromone blend that females produce and males respond to differs between strains of O. nubilalis. Populations also vary in female oviposition preference for and larval performance on maize (C4) and nonmaize (C3) host plants. The relative contributions of sexual and ecological trait variation to the genetic structure of O. nubilalis remains unknown. Host-plant use (13 C/14 C ratios) and genetic differentiation were estimated among sympatric E and Z pheromone strain O. nubilalis males collected in sex-pheromone baited traps at 12 locations in Pennsylvania and New York between 2007 and 2010. Among genotypes at 65 single nucleotide polymorphism marker loci, variance at a position in the pheromone gland fatty acyl-reductase (pgfar) gene at the locus responsible for determining female pheromone ratio (Pher) explained 64% of the total genetic differentiation between males attracted to different pheromones (male response, Resp), providing evidence of sexual inter-selection at these unlinked loci. Principal coordinate, Bayesian clustering, and distance-based redundancy analysis (dbRDA) demonstrate that host plant history or geography does not significantly contribute to population variation or differentiation among males. In contrast, these analyses indicate that pheromone response and pgfar-defined strain contribute significantly to population genetic differentiation. This study suggests that behavioural divergence probably plays a larger role in driving genetic variation compared to host plant-defined ecological adaptation.
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Affiliation(s)
- Brad S Coates
- Corn Insects & Crop Genetics Research Unit, USDA-ARS, Ames, IA, USA
| | - Genevieve M Kozak
- Department of Biology, University of Massachusetts-Dartmouth, Dartmouth, MA, USA.,Department of Biology, Tufts University, Medford, MA, USA
| | - Kyung Seok Kim
- Department of Natural Resource Ecology and Management, Iowa State University, Ames, IA, USA
| | - Jing Sun
- Department of Entomology, Iowa State University, Ames, IA, USA
| | - Yangzhou Wang
- Jilin Academy of Agricultural Sciences, Changchun, China
| | | | - Erik B Dopman
- Department of Biology, Tufts University, Medford, MA, USA
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4
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Orsucci M, Audiot P, Nidelet S, Dorkeld F, Pommier A, Vabre M, Severac D, Rohmer M, Gschloessl B, Streiff R. Transcriptomic response of female adult moths to host and non-host plants in two closely related species. BMC Evol Biol 2018; 18:145. [PMID: 30236059 PMCID: PMC6148789 DOI: 10.1186/s12862-018-1257-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 08/30/2018] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND Divergent selection has been shown to promote speciation in many taxa and especially in phytophagous insects. In the Ostrinia species complex, the European corn borer (ECB) and adzuki bean borer (ABB) are two sibling species specialized to different host plants. The first is a well-known maize pest, whereas the second is a polyphagous species associated with various dicotyledons. Their specialization to host plants is driven by morphological, behavioral and physiological adaptations. In particular, previous studies have shown that ECB and ABB display marked behavior with regard to plant choice during oviposition, involving specific preference and avoidance mechanisms. In this study, our goal was to identify the mechanisms underlying this host-plant specialization in adult females through an analysis of their gene expression. We assembled and annotated a de novo reference transcriptome and measured differences in gene expression between ECB and ABB females, and between environments. We related differentially expressed genes to host preference behavior, and highlighted the functional categories involved. We also conducted a specific analysis of chemosensory genes, which are considered to be good candidates for host recognition before oviposition. RESULTS We recorded more differentially expressed genes in ECB than in ABB samples, and noticed that the majority of genes potentially involved in the host preference were different between the two species. At the functional level, the response to plant environment in adult females involved many processes, including the metabolism of carbohydrates, lipids, proteins, and amino acids; detoxification mechanisms and immunity; and the chemosensory repertoire (as expected). Until now, most of the olfactory receptors described in Ostrinia spp. had been tested for their putative role in pheromone recognition by males. Here we observed that one specific olfactory receptor was clearly associated with ECB's discrimination between maize and mugwort conditions, highlighting a potential new candidate involved in plant odor discrimination in adult females. CONCLUSIONS Our results are a first step toward the identification of candidate genes and functions involved in chemosensory processes, carbohydrate metabolism, and virus and retrovirus dynamics. These candidates provide new avenues for research into understanding the role of divergent selection between different environments in species diversification.
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Affiliation(s)
- M. Orsucci
- CBGP, INRA, CIRAD, IRD, Montpellier SupAgro, Univ Montpellier, Montpellier, France
- DGIMI, INRA, Univ Montpellier, Montpellier, France
- Present address: Department of Ecology and Genetics, EBC, Uppsala University, Norbyvägen 18D, 75236 Uppsala, Sweden
| | - P. Audiot
- CBGP, INRA, CIRAD, IRD, Montpellier SupAgro, Univ Montpellier, Montpellier, France
| | - S. Nidelet
- CBGP, INRA, CIRAD, IRD, Montpellier SupAgro, Univ Montpellier, Montpellier, France
| | - F. Dorkeld
- CBGP, INRA, CIRAD, IRD, Montpellier SupAgro, Univ Montpellier, Montpellier, France
| | - A. Pommier
- CBGP, INRA, CIRAD, IRD, Montpellier SupAgro, Univ Montpellier, Montpellier, France
| | | | - D. Severac
- MGX-Montpellier GenomiX, c/o Institut de Génomique Fonctionnelle, 34094 Montpellier Cedex 5, France
| | - M. Rohmer
- MGX-Montpellier GenomiX, c/o Institut de Génomique Fonctionnelle, 34094 Montpellier Cedex 5, France
| | - B. Gschloessl
- CBGP, INRA, CIRAD, IRD, Montpellier SupAgro, Univ Montpellier, Montpellier, France
| | - R. Streiff
- CBGP, INRA, CIRAD, IRD, Montpellier SupAgro, Univ Montpellier, Montpellier, France
- DGIMI, INRA, Univ Montpellier, Montpellier, France
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5
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Orsucci M, Audiot P, Dorkeld F, Pommier A, Vabre M, Gschloessl B, Rialle S, Severac D, Bourguet D, Streiff R. Larval transcriptomic response to host plants in two related phytophagous lepidopteran species: implications for host specialization and species divergence. BMC Genomics 2018; 19:265. [PMID: 29669517 PMCID: PMC5907310 DOI: 10.1186/s12864-018-4589-x] [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: 12/01/2017] [Accepted: 03/08/2018] [Indexed: 11/17/2022] Open
Abstract
Background Most phytophagous insects have morphological, behavioral and physiological adaptations allowing them to specialize on one or a few plant species. Identifying the mechanisms involved in host plant specialization is crucial to understand the role of divergent selection between different environments in species diversification, and to identify sustainable targets for the management of insect pest species. In the present study, we measured larval phenotypic and transcriptomic responses to host plants in two related phytophagous lepidopteran species: the European corn borer (ECB), a worldwide pest of maize, and the adzuki bean borer (ABB), which feeds of various dicotyledons. Our aim was to identify the genes and functions underlying host specialization and/or divergence between ECB and ABB. Results At the phenotypic level, we observed contrasted patterns of survival, weight gain and developmental time between ECB and ABB, and within ECB and ABB reared on two different host plants. At the transcriptomic level, around 8% of the genes were differentially expressed (DE) between species and/or host plant. 70% of these DE genes displayed a divergent pattern of expression between ECB and ABB, regardless of the host, while the remaining 30% were involved in the plastic response between hosts. We further categorized plastic DE genes according to their parallel or opposite pattern between ECB and ABB to specifically identify candidate genes involved in the species divergence by host specialization. These candidates highlighted a comprehensive response, involving functions related to plant recognition, digestion, detoxification, immunity and development. Last, we detected viral, bacterial, and yeast genes whose incidence contrasted ECB and ABB samples, and maize and mugwort conditions. We suggest that these microorganism communities might influence the survival, metabolism and defense patterns observed in ECB and ABB larvae. Conclusions The comprehensive approach developed in the present study allowed to identify phenotypic specialization patterns and underlying candidate molecular mechanisms, and highlighted the putative role of microorganisms in the insect-host plant interaction. These findings offer the opportunity to pinpoint specific and sustainable molecular or physiological targets for the regulation of ECB pest populations. Electronic supplementary material The online version of this article (10.1186/s12864-018-4589-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- M Orsucci
- CBGP UMR 1062, INRA-IRD-CIRAD-Montpellier SupAgro, Montferrier sur Lez, Montpellier, France. .,DGIMI UMR 1333, INRA-Université de Montpellier, Montpellier, France. .,Present address: Department of Ecology and Genetics, EBC, Uppsala University, Norbyvägen 18D, 75236, Uppsala, Sweden.
| | - P Audiot
- CBGP UMR 1062, INRA-IRD-CIRAD-Montpellier SupAgro, Montferrier sur Lez, Montpellier, France
| | - F Dorkeld
- CBGP UMR 1062, INRA-IRD-CIRAD-Montpellier SupAgro, Montferrier sur Lez, Montpellier, France
| | - A Pommier
- CBGP UMR 1062, INRA-IRD-CIRAD-Montpellier SupAgro, Montferrier sur Lez, Montpellier, France
| | - M Vabre
- MELGUEIL DIASCOPE UE 0398, INRA, Mauguio, France
| | - B Gschloessl
- CBGP UMR 1062, INRA-IRD-CIRAD-Montpellier SupAgro, Montferrier sur Lez, Montpellier, France
| | - S Rialle
- MGX-Montpellier GenomiX, c/o Institut de Génomique Fonctionnelle, Montpellier, France
| | - D Severac
- MGX-Montpellier GenomiX, c/o Institut de Génomique Fonctionnelle, Montpellier, France
| | - D Bourguet
- CBGP UMR 1062, INRA-IRD-CIRAD-Montpellier SupAgro, Montferrier sur Lez, Montpellier, France
| | - R Streiff
- CBGP UMR 1062, INRA-IRD-CIRAD-Montpellier SupAgro, Montferrier sur Lez, Montpellier, France.,DGIMI UMR 1333, INRA-Université de Montpellier, Montpellier, France
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6
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Gschloessl B, Dorkeld F, Audiot P, Bretaudeau A, Kerdelhué C, Streiff R. De novo genome and transcriptome resources of the Adzuki bean borer Ostrinia scapulalis (Lepidoptera: Crambidae). Data Brief 2018; 17:781-787. [PMID: 29785409 PMCID: PMC5958680 DOI: 10.1016/j.dib.2018.01.073] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Revised: 01/23/2018] [Accepted: 01/25/2018] [Indexed: 11/25/2022] Open
Abstract
We present a draft genome assembly with a de novo prediction and automated functional annotation of coding genes, and a reference transcriptome of the Adzuki bean borer, Ostrinia scapulalis, based on RNA sequencing of various tissues and developmental stages. The genome assembly spans 419 Mb, has a GC content of 37.4% and includes 26,120 predicted coding genes. The reference transcriptome holds 33,080 unigenes and contains a high proportion of a set of genes conserved in eukaryotes and arthropods, used as quality assessment of the reconstructed transcripts. The new genomic and transcriptomic data presented here significantly enrich the public sequence databases for the Crambidae and Lepidoptera, and represent useful resources for future researches related to the evolution and the adaptation of phytophagous moths. The genome and transcriptome assemblies have been deposited and made accessible via a NCBI BioProject (id PRJNA390510) and the LepidoDB database (http://bipaa.genouest.org/sp/ostrinia_scapulalis/).
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Affiliation(s)
- B Gschloessl
- CBGP, INRA, CIRAD, IRD, Montpellier SupAgro, Univ Montpellier, Montpellier, France
| | - F Dorkeld
- CBGP, INRA, CIRAD, IRD, Montpellier SupAgro, Univ Montpellier, Montpellier, France
| | - P Audiot
- CBGP, INRA, CIRAD, IRD, Montpellier SupAgro, Univ Montpellier, Montpellier, France
| | - A Bretaudeau
- INRA, UMR Institut de Génétique, Environnement et Protection des Plantes (IGEPP), BioInformatics Platform for Agroecosystems Arthropods (BIPAA), Campus Beaulieu, Rennes, France.,INRIA, IRISA, GenOuest Core Facility, Campus de Beaulieu, Rennes, France
| | - C Kerdelhué
- CBGP, INRA, CIRAD, IRD, Montpellier SupAgro, Univ Montpellier, Montpellier, France
| | - R Streiff
- CBGP, INRA, CIRAD, IRD, Montpellier SupAgro, Univ Montpellier, Montpellier, France
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7
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Calcagno V, Mitoyen C, Audiot P, Ponsard S, Gao G, Lu Z, Wang Z, He K, Bourguet D. Parallel evolution of behaviour during independent host-shifts following maize introduction into Asia and Europe. Evol Appl 2017; 10:881-889. [PMID: 29151879 PMCID: PMC5680425 DOI: 10.1111/eva.12481] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 03/07/2017] [Indexed: 11/30/2022] Open
Abstract
Maize was introduced into opposite sides of Eurasia 500 years ago, in Western Europe and in Asia. This caused two host-shifts in the phytophagous genus Ostrinia; O. nubilalis (the European corn borer; ECB) and O. furnacalis (the Asian corn borer; ACB) are now major pests of maize worldwide. They originated independently from Dicot-feeding ancestors, similar to O. scapulalis (the Adzuki bean borer; ABB). Unlike other host-plants, maize is yearly harvested, and harvesting practices impose severe mortality on larvae found above the cut-off line. Positive geotaxis in the ECB has been proposed as a behavioural adaptation to harvesting practices, allowing larvae to move below the cut-off line and thus escape harvest mortality. Here, we test whether the same behavioural adaptation evolved independently in Europe and in Asia. We sampled eight genetically differentiated ECB, ACB and ABB populations in France and China and monitored geotaxis through the entire larval development in artificial stacks mimicking maize stems. We find that all ECB and ACB populations show a similar tendency to move down during the latest larval stages, a behaviour not observed in any European or Asian ABB population. The behaviour is robustly expressed regardless of larval density, development mode or environmental conditions. Our results indicate that maize introduction triggered parallel behavioural adaptations in Europe and Asia, harvest selection presumably being the main driver.
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Affiliation(s)
| | - Clémentine Mitoyen
- INRAUMR Centre de Biologie pour la Gestion des Populations (CBGP)Montferrier‐sur‐LezFrance
| | - Philippe Audiot
- INRAUMR Centre de Biologie pour la Gestion des Populations (CBGP)Montferrier‐sur‐LezFrance
| | - Sergine Ponsard
- UMR5174 EDB (Laboratoire Évolution & Diversité Biologique)CNRSENFAUniversité Toulouse 3 Paul SabatierToulouseFrance
- CNRSUMR5174 EDBToulouseFrance
| | - Gui‐Zhen Gao
- Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqiChina
- College of Forestry and HorticultureXinjiang Agricultural UniversityUrumqiChina
| | - Zhao‐Zhi Lu
- Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqiChina
| | - Zhen‐Ying Wang
- State Key Laboratory for the Biology of the Plant Diseases and Insect PestsInstitute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
| | - Kang‐Lai He
- State Key Laboratory for the Biology of the Plant Diseases and Insect PestsInstitute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
| | - Denis Bourguet
- INRAUMR Centre de Biologie pour la Gestion des Populations (CBGP)Montferrier‐sur‐LezFrance
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8
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Orsucci M, Audiot P, Pommier A, Raynaud C, Ramora B, Zanetto A, Bourguet D, Streiff R. Host specialization involving attraction, avoidance and performance, in two phytophagous moth species. J Evol Biol 2015; 29:114-25. [PMID: 26406269 DOI: 10.1111/jeb.12766] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Revised: 09/11/2015] [Accepted: 09/18/2015] [Indexed: 11/29/2022]
Abstract
Host specialization plays a key role in the extreme diversification of phytophagous insects. Whereas proximate mechanisms of specialization have been studied extensively, their consequences for species divergence remain unclear. Preference for, and performance on hosts are thought to be a major source of divergence in phytophagous insects. We assessed these major components of specialization in two moth species, the European corn borer (ECB) and the Adzuki bean borer (ABB), by testing their oviposition behaviour in different conditions (choice or no-choice set-ups) and their performances, by reciprocal transplant at the larval stage on the usual host and an alternative host plant. We demonstrated that both ABB and ECB have a strong preference for their host plants for oviposition, but that relative larval performances on the usual host and an alternative host differed according to the experiment and the trait considered (weight or survival). Finally, we show for the first time that the preference for maize in ECB conceals a strong avoidance of mugwort. The differences in performance, attraction and avoidance between ECB and ABB are discussed in the light of the underlying mechanisms and divergence process.
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Affiliation(s)
- M Orsucci
- CBGP UMR 1062, INRA-IRD-CIRAD-Montpellier SupAgro, Montferrier sur Lez, France.,DGIMI UMR 1333, INRA-Université de Montpellier, Montpellier, France
| | - P Audiot
- CBGP UMR 1062, INRA-IRD-CIRAD-Montpellier SupAgro, Montferrier sur Lez, France
| | - A Pommier
- CBGP UMR 1062, INRA-IRD-CIRAD-Montpellier SupAgro, Montferrier sur Lez, France
| | - C Raynaud
- MELGUEIL DIASCOPE UE 0398, INRA, Mauguio, France
| | - B Ramora
- MELGUEIL DIASCOPE UE 0398, INRA, Mauguio, France
| | - A Zanetto
- MELGUEIL DIASCOPE UE 0398, INRA, Mauguio, France
| | - D Bourguet
- CBGP UMR 1062, INRA-IRD-CIRAD-Montpellier SupAgro, Montferrier sur Lez, France
| | - R Streiff
- CBGP UMR 1062, INRA-IRD-CIRAD-Montpellier SupAgro, Montferrier sur Lez, France.,DGIMI UMR 1333, INRA-Université de Montpellier, Montpellier, France
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9
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Bourguet D, Ponsard S, Streiff R, Meusnier S, Audiot P, Li J, Wang ZY. 'Becoming a species by becoming a pest' or how two maize pests of the genus Ostrinia possibly evolved through parallel ecological speciation events. Mol Ecol 2015; 23:325-42. [PMID: 24289254 DOI: 10.1111/mec.12608] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Revised: 11/15/2013] [Accepted: 11/19/2013] [Indexed: 11/26/2022]
Abstract
New agricultural pest species attacking introduced crops may evolve from pre-existing local herbivores by ecological speciation, thereby becoming a species by becoming a pest. We compare the evolutionary pathways by which two maize pests (the Asian and the European corn borers, ACB and ECB) in the genus Ostrinia (Lepidoptera, Crambidae) probably diverged from an ancestral species close to the current Adzuki bean borer (ABB). We typed larval Ostrinia populations collected on maize and dicotyledons across China and eastern Siberia, at microsatellite and mitochondrial loci. We found only two clusters: one on maize (as expected) and a single one on dicotyledons despite differences in male mid-tibia morphology, suggesting that all individuals from dicotyledons belonged to the ABB. We found evidence for migrants and hybrids on both host plant types. Hybrids suggest that field reproductive isolation is incomplete between ACB and ABB. Interestingly, a few individuals with an 'ABB-like' microsatellite profile collected on dicotyledons had 'ACB' mtDNA rather than 'ABB-like' mtDNA, whereas the reverse was never found on maize. This suggests asymmetrical gene flow directed from the ACB towards the ABB. Hybrids and backcrosses in all directions were obtained in no-choice tests. In laboratory conditions, they survived as well as parental strain individuals. In Xinjiang, we found ACB and ECB in sympatry, but no hybrids. Altogether, our results suggest that reproductive isolation between ACB and ABB is incomplete and mostly prezygotic. This points to ecological speciation as a possible evolutionary scenario, as previously found for ECB and ABB in Europe.
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Affiliation(s)
- Denis Bourguet
- Centre de Biologie pour la Gestion des Populations (CBGP), UMR INRA-IRD-CIRAD-Montpellier SupAgro, Campus International de Baillarguet, 34988, Montferrier-sur-Lez Cedex, France
| | - Sergine Ponsard
- UMR 5174 EDB (Laboratoire Evolution & Diversité Biologique), Université de Toulouse, ENFA, 118 route de Narbonne, F-31062, Toulouse, France.,UMR 5174 EDB, CNRS, Université Paul Sabatier, F-31062, Toulouse, France.,State Key Laboratory for the Biology of the Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No.2 West Yuanmingyuan Road, Beijing, 100193, China.,UMR 5175, CNRS, Centre d'Ecologie Fonctionnelle et Evolutive (CEFE), 1919 route de Mende, Montpellier Cedex 05, 34293, Montpellier, France
| | - Rejane Streiff
- Centre de Biologie pour la Gestion des Populations (CBGP), UMR INRA-IRD-CIRAD-Montpellier SupAgro, Campus International de Baillarguet, 34988, Montferrier-sur-Lez Cedex, France
| | - Serge Meusnier
- Centre de Biologie pour la Gestion des Populations (CBGP), UMR INRA-IRD-CIRAD-Montpellier SupAgro, Campus International de Baillarguet, 34988, Montferrier-sur-Lez Cedex, France
| | - Philippe Audiot
- Centre de Biologie pour la Gestion des Populations (CBGP), UMR INRA-IRD-CIRAD-Montpellier SupAgro, Campus International de Baillarguet, 34988, Montferrier-sur-Lez Cedex, France
| | - Jing Li
- UMR 5174 EDB (Laboratoire Evolution & Diversité Biologique), Université de Toulouse, ENFA, 118 route de Narbonne, F-31062, Toulouse, France.,UMR 5174 EDB, CNRS, Université Paul Sabatier, F-31062, Toulouse, France.,State Key Laboratory for the Biology of the Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No.2 West Yuanmingyuan Road, Beijing, 100193, China.,School of biological technology, Xi'an University of Arts and Science, No.168 South Taibai Road, Xi'an, Shaanxi Province, 710065, China
| | - Zhen-Ying Wang
- State Key Laboratory for the Biology of the Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No.2 West Yuanmingyuan Road, Beijing, 100193, China
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10
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Genetic mapping of two components of reproductive isolation between two sibling species of moths, Ostrinia nubilalis and O. scapulalis. Heredity (Edinb) 2013; 112:370-81. [PMID: 24220089 DOI: 10.1038/hdy.2013.113] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Revised: 07/16/2013] [Accepted: 09/06/2013] [Indexed: 01/24/2023] Open
Abstract
We report the quantitative trait loci (QTL) mapping of reproductive isolation traits between Ostrinia nubilalis (the European corn borer) and its sibling species O. scapulalis (the Adzuki bean borer), focusing on two traits: mating isolation (mi) and pheromone production (Pher). Four genetic maps were generated from two backcross families, with two maps (one chromosomal map and one linkage map) per backcross. We located 165-323 AFLP markers on these four maps, resulting in the identification of 27-31 linkage groups, depending on the map considered. No-choice mating experiments with the offspring of each backcross led to the detection of at least two QTLs for mi in different linkage groups. QTLs underlying Pher were located in a third linkage group. The Z heterochromosome was identified by a specific marker (Tpi) and did not carry any of these QTLs. Finally, we considered the global divergence between the two sibling species, distortions of segregation throughout the genome, and the location and effect of mi and Pher QTLs in light of the known candidate genes for reproductive isolation within the genus Ostrinia and, more broadly, in phytophagous insects.
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11
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Alexandre H, Ponsard S, Bourguet D, Vitalis R, Audiot P, Cros-Arteil S, Streiff R. When history repeats itself: exploring the genetic architecture of host-plant adaptation in two closely related lepidopteran species. PLoS One 2013; 8:e69211. [PMID: 23874914 PMCID: PMC3709918 DOI: 10.1371/journal.pone.0069211] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Accepted: 06/11/2013] [Indexed: 11/18/2022] Open
Abstract
The genus Ostrinia includes two allopatric maize pests across Eurasia, namely the European corn borer (ECB, O. nubilalis) and the Asian corn borer (ACB, O. furnacalis). A third species, the Adzuki bean borer (ABB, O. scapulalis), occurs in sympatry with both the ECB and the ACB. The ABB mostly feeds on native dicots, which probably correspond to the ancestral host plant type for the genus Ostrinia. This situation offers the opportunity to characterize the two presumably independent adaptations or preadaptations to maize that occurred in the ECB and ACB. In the present study, we aimed at deciphering the genetic architecture of these two adaptations to maize, a monocot host plant recently introduced into Eurasia. To this end, we performed a genome scan analysis based on 684 AFLP markers in 12 populations of ECB, ACB and ABB. We detected 2 outlier AFLP loci when comparing French populations of the ECB and ABB, and 9 outliers when comparing Chinese populations of the ACB and ABB. These outliers were different in both countries, and we found no evidence of linkage disequilibrium between any two of them. These results suggest that adaptation or preadaptation to maize relies on a different genetic architecture in the ECB and ACB. However, this conclusion must be considered in light of the constraints inherent to genome scan approaches and of the intricate evolution of adaptation and reproductive isolation in the Ostrinia spp. complex.
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Affiliation(s)
- Hermine Alexandre
- INRA, UMR CBGP (INRA, IRD, CIRAD, Montpellier SupAgro), Montferrier-sur-Lez, France
- Université de Toulouse, ENFA, UMR5174 EDB (Laboratoire Évolution & Diversité Biologique), Toulouse, France
- CNRS, Université Paul Sabatier, UMR5174 EDB, Toulouse, France
| | - Sergine Ponsard
- Université de Toulouse, ENFA, UMR5174 EDB (Laboratoire Évolution & Diversité Biologique), Toulouse, France
- CNRS, Université Paul Sabatier, UMR5174 EDB, Toulouse, France
| | - Denis Bourguet
- INRA, UMR CBGP (INRA, IRD, CIRAD, Montpellier SupAgro), Montferrier-sur-Lez, France
| | - Renaud Vitalis
- INRA, UMR CBGP (INRA, IRD, CIRAD, Montpellier SupAgro), Montferrier-sur-Lez, France
| | - Philippe Audiot
- INRA, UMR CBGP (INRA, IRD, CIRAD, Montpellier SupAgro), Montferrier-sur-Lez, France
| | - Sandrine Cros-Arteil
- INRA, UMR CBGP (INRA, IRD, CIRAD, Montpellier SupAgro), Montferrier-sur-Lez, France
| | - Réjane Streiff
- INRA, UMR CBGP (INRA, IRD, CIRAD, Montpellier SupAgro), Montferrier-sur-Lez, France
- * E-mail:
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12
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Gschloessl B, Beyne E, Audiot P, Bourguet D, Streiff R. De novo transcriptomic resources for two sibling species of moths: Ostrinia nubilalis and O. scapulalis. BMC Res Notes 2013; 6:73. [PMID: 23445568 PMCID: PMC3599821 DOI: 10.1186/1756-0500-6-73] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 02/20/2013] [Indexed: 11/10/2022] Open
Abstract
Background This study aimed at enhancing the transcriptomic resources for two sibling species of moths, Ostrinia scapulalis (Adzuki bean borer) and Ostrinia nubilalis (European corn borer), as a foundation for future researches on their divergence history. Previous works on these species had shown that their genetic divergence was low, while they were reproductively isolated in natura and specialized on different host plants. Comparative genomic resources will help facilitate the understanding of the mechanisms involved in this isolation and adaptation to the host plants. Despite their fundamental interest, these species still lack the genomic resources to thoroughly identify candidate genes for functions of interest. We present here a high throughput sequencing and de novo transcriptome assembly for these two sibling species in line with this objective of comparative genomics. Results Based on 322,504 and 307,622 reads of 454 sequencing for O. scapulalis and O. nubilalis respectively, we reconstructed 11,231 and 10,773 transcripts, of which 40% were functionally annotated by BLAST analyzes. We determined the level of completeness of both assemblies as well as the recovery level of published Ostrinia genomic resources. Gene ontology (GO) of common and species-specific de novo transcripts did not reveal GO terms significantly enriched in one or the other species. By applying stringent homology searches on transcripts common to O. scapulalis and O. nubilalis, we identified a set of homologous transcripts, with a mean nucleotide identity value of 98.1%. In this set, the most divergent transcripts revealed candidate genes involved in developmental, sensorial and pathogen defense processes. Conclusions This data greatly increases the genomic resources of Ostrinia species and constitute a solid skeleton for future comparative analyzes of expression or diversity, despite we show that the transcriptomes for both species have not been assembled at full completion. In addition, we provide a set of homologous transcripts together with their annotation as a source of candidate genes for comparative analyzes.
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Affiliation(s)
- Bernhard Gschloessl
- Centre de Biologie pour Gestion des Populations UMR INRA-IRD-CIRAD-Montpellier SupAgro, Campus International de Baillarguet, Montferrier-sur-Lez Cedex 34988, France.
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13
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Midamegbe A, Vitalis R, Malausa T, Delava E, Cros-Arteil S, Streiff R. Scanning the European corn borer (Ostrinia spp.) genome for adaptive divergence between host-affiliated sibling species. Mol Ecol 2011; 20:1414-30. [PMID: 21375617 DOI: 10.1111/j.1365-294x.2011.05035.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
It has recently been shown that the European corn borer, a major pest of maize crops, is actually composed of two genetically differentiated and reproductively isolated taxa, which are found in sympatry over a wide geographical range in Eurasia. Each taxon is adapted to specific host plants: Ostrinia nubilalis feeds mainly on maize, while O. scapulalis feeds mainly on hop or mugwort. Here, we present a genome scan approach as a first step towards an integrated molecular analysis of the adaptive genomic divergence between O. nubilalis and O. scapulalis. We analysed 609 AFLP marker loci in replicate samples of sympatric populations of Ostrinia spp. collected on maize, hop and mugwort, in France. Using two genome scan methods based on the analysis of population differentiation, we found a set of 28 outlier loci that departed from the neutral expectation in one or the other method (of which a subset of 14 loci were common to both methods), which showed a significantly increased differentiation between O. nubilalis and O. scapulalis, when compared to the rest of the genome. A subset of 12 outlier loci were sequenced, of which 7 were successfully re-amplified as target candidate loci. Three of these showed homology with annotated lepidopteran sequences from public nucleotide databases.
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Affiliation(s)
- Afiwa Midamegbe
- Institut National de la Recherche Agronomique, UMR CBGP (INRA-IRD-CIRAD-Montpellier SupAgro), Campus International de Baillarguet, CS 30016, Montferrier sur Lez Cedex, France
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14
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Dopman EB, Robbins PS, Seaman A. Components of reproductive isolation between North American pheromone strains of the European corn borer. Evolution 2010; 64:881-902. [PMID: 19895559 PMCID: PMC2857697 DOI: 10.1111/j.1558-5646.2009.00883.x] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Of 12 potential reproductive isolating barriers between closely related Z- and E-pheromone strains of the European corn borer moth (Ostrinia nubilalis), seven significantly reduced gene flow but none were complete, suggesting that speciation in this lineage is a gradual process in which multiple barriers of intermediate strength accumulate. Estimation of the cumulative effect of all barriers resulted in nearly complete isolation (>99%), but geographic variation in seasonal isolation allowed as much as approximately 10% gene flow. With the strongest barriers arising from mate-selection behavior or ecologically relevant traits, sexual and natural selection are the most likely evolutionary processes driving population divergence. A recent multilocus genealogical study corroborates the roles of selection and gene flow (Dopman et al. 2005), because introgression is supported at all loci besides Tpi, a sex-linked gene. Tpi reveals strains as exclusive groups, possesses signatures of selection, and is tightly linked to a QTL that contributes to seasonal isolation. With more than 98% of total cumulative isolation consisting of prezygotic barriers, Z and E strains of ECB join a growing list of taxa in which species boundaries are primarily maintained by the prevention of hybridization, possibly because premating barriers evolve during early stages of population divergence.
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Affiliation(s)
- Erik B. Dopman
- Department of Biology, Tufts University, 163 Packard Avenue, Medford, MA 02155
| | - Paul S. Robbins
- Department of Entomology, Cornell University, Geneva, NY 14456
| | - Abby Seaman
- Integrated Pest Management Program, Cornell University, Geneva, NY 14456
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15
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Jongsma MA, Gould F, Legros M, Yang L, van Loon JJA, Dicke M. Insect oviposition behavior affects the evolution of adaptation to Bt crops: consequences for refuge policies. Evol Ecol 2010. [DOI: 10.1007/s10682-010-9368-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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16
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PÉLISSIÉ B, PONSARD S, TOKAREV YS, AUDIOT P, PÉLISSIER C, SABATIER R, MEUSNIER S, CHAUFAUX J, DELOS M, CAMPAN E, MALYSH JM, FROLOV AN, BOURGUET D. Did the introduction of maize into Europe provide enemy-free space toOstrinia nubilalis? Parasitism differences between two sibling species of the genusOstrinia. J Evol Biol 2010; 23:350-61. [DOI: 10.1111/j.1420-9101.2009.01903.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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17
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Piesik D, Rochat D, van der Pers J, Marion-Poll F. Pulsed Odors from Maize or Spinach Elicit Orientation in European Corn Borer Neonate Larvae. J Chem Ecol 2009; 35:1032-42. [DOI: 10.1007/s10886-009-9676-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2009] [Revised: 07/28/2009] [Accepted: 08/03/2009] [Indexed: 11/27/2022]
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18
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Malausa T, Dalecky A, Ponsard S, Audiot P, Streiff R, Chaval Y, Bourguet D. Genetic structure and gene flow in French populations of two Ostrinia taxa: host races or sibling species? Mol Ecol 2007; 16:4210-22. [PMID: 17822415 DOI: 10.1111/j.1365-294x.2007.03457.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Most models of ecological speciation concern phytophagous insects in which speciation is thought to be driven by host shifts and subsequent adaptations of populations. Despite the ever-increasing number of studies, the current evolutionary status of most models remains incompletely resolved, as estimates of gene flow between taxa remain extremely rare. We studied the population genetics of two taxa of the Ostrinia genus--one feeding mainly on maize and the other on mugwort and hop--occurring in sympatry throughout France. The actual level of divergence of these taxa was unknown because the genetic structure of populations had been investigated over a limited geographical area and the magnitude of gene flow between populations had not been estimated. We used 11 microsatellite markers to investigate the genetic structure of populations throughout France and the extent of gene flow between the two Ostrinia taxa at several sites at which they are sympatric. We observed clear genetic differentiation between most populations collected on the typical respective hosts of each taxon. However, populations displaying intermediate allelic frequencies were found on hop plants in southern France. Individual assignments revealed that this result could be accounted for by the presence of both taxa on the same host. Gene flow, estimated by determining the proportion of hybrids detected, was low: probably<1% per generation, regardless of site. This indicates that the two Ostrinia taxa have reached a high level of genetic divergence and should be considered sibling species rather than host races.
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Affiliation(s)
- T Malausa
- Centre de Biologie et de Gestion des Populations (CBGP), UMR INRA-IRD-CIRAD-SupAgro, Institut National de la Recherche Agronomique, Campus International de Baillarguet, 34 988 Montferrier/Lez, France.
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Malausa T, Leniaud L, Martin JF, Audiot P, Bourguet D, Ponsard S, Lee SF, Harrison RG, Dopman E. Molecular differentiation at nuclear loci in French host races of the European corn borer (Ostrinia nubilalis). Genetics 2007; 176:2343-55. [PMID: 17603115 PMCID: PMC1950636 DOI: 10.1534/genetics.107.072108] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
French populations of the European corn borer consist of two sympatric and genetically differentiated host races. As such, they are well suited to study processes that could be involved in sympatric speciation, but the initial conditions of host-race divergence need to be elucidated. Gene genealogies can provide insight into the processes involved in speciation. We used DNA sequences of four nuclear genes to (1) document the genetic structure of the two French host races previously delineated with allozyme markers, (2) find genes directly or indirectly involved in reproductive isolation between host races, and (3) estimate the time since divergence of the two taxa and see whether this estimate is compatible with this divergence being the result of a host shift onto maize after its introduction into Europe approximately 500 years ago. Gene genealogies revealed extensive shared polymorphism, but confirmed the previously observed genetic differentiation between the two host races. Significant departures from the predictions of neutral molecular evolution models were detected at three loci but were apparently unrelated to reproductive isolation between host races. Estimates of time since divergence between French host races varied from approximately 75,000 to approximately 150,000 years, suggesting that the two taxa diverged recently but probably long before the introduction of maize into Europe.
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Affiliation(s)
- Thibaut Malausa
- Laboratoire Dynamique de la Biodiversité, UMR CNRS 5172, Université P. Sabatier-Toulouse III, 118 Route de Narbonne, 31 062 Toulouse Cedex 09, france.
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