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1. Host plants and insecticides shape the evolution of genetic and clonal diversity in a major aphid crop pest

Author

Lise Roy, Benoit Barrès, Cécile Capderrey, Frédérique Mahéo, Annie Micoud, Maurice Hullé, and Jean‐Christophe Simon

Subjects
agricultural landscape, gene flow, insecticide resistance, Myzus persicae, temporal dynamics, Evolution, QH359-425
Abstract

Abstract Understanding the spatiotemporal dynamics of pesticide resistance at the landscape scale is essential to anticipate the evolution and spread of new resistance phenotypes. In crop mosaics, host plant specialization in pest populations is likely to dampen the spread of pesticide resistance between different crops even in mobile pests such as aphids. Here, we assessed the contribution of host‐based genetic differentiation to the dynamics of resistance alleles in Myzus persicae, a major aphid pest which displays several insecticide resistance mechanisms. We obtained a representative sample of aphids from a crop mosaic through a suction trap for 7 years and from various crops as a reference collection. We genotyped these aphids at 14 microsatellite markers and four insecticide‐resistant loci, analyzed the genetic structure, and assigned host‐based genetic groups from field‐collected aphids. Four well‐defined genetic clusters were found in aerial samples, three of which with strong association with host‐plants. The fourth group was exclusive to aerial samples and highly divergent from the others, suggesting mixture with a closely related taxon of M. persicae associated with unsampled plants. We found a sharp differentiation between individuals from peach and herbaceous plants. Individuals from herbaceous hosts were separated into two genetic clusters, one more strongly associated with tobacco. The 4‐loci resistance genotypes showed a strong association with the four genetic clusters, indicative of barriers to the spread of resistance. However, we found a small number of clones with resistant alleles on multiple host‐plant species, which may spread insecticide resistance between crops. The 7‐year survey revealed a rapid turn‐over of aphid genotypes as well as the emergence, frequency increase and persistence of clones with resistance to several families of insecticides. This study highlights the importance of considering landscape‐scale population structure to identify the risk of emergence and spread of insecticide resistance for a particular crop.

Published
2022
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2. A Link Between Communities of Protective Endosymbionts and Parasitoids of the Pea Aphid Revealed in Unmanipulated Agricultural Systems

Author

Mélanie Leclair, Christelle Buchard, Frédérique Mahéo, Jean-Christophe Simon, and Yannick Outreman

Subjects
protective symbioses, insect parasitoids, parasitism pressure, symbiont communities, field approach, Acyrthosiphon pisum, Evolution, QH359-425, Ecology, QH540-549.5
Abstract

In the last decade, the influence of microbial symbionts on ecological and physiological traits of their hosts has been increasingly recognized. However, most of these effects have been revealed under laboratory conditions, which oversimplifies the complexity of the factors involved in the dynamics of symbiotic associations in nature. The pea aphid, Acyrthosiphon pisum, forms a complex of plant-adapted biotypes, which strongly differ in the prevalence of their facultative endosymbionts. Some of the facultative endosymbionts of A. pisum have been shown to confer protection against natural enemies, among which Hamiltonella defensa is known to protect its host from parasitoid wasps. Here, we tested under natural conditions whether the endosymbiont communities of different A. pisum biotypes had a protective effect on their hosts and whether endosymbiotic associations and parasitoid communities associated with the pea aphid complex were linked. A space-time monitoring of symbiotic associations, parasitoid pressure and parasitoid communities was carried out in three A. pisum biotypes respectively specialized on Medicago sativa (alfalfa), Pisum sativum (pea), and Trifolium sp. (clover) throughout the whole cropping season. While symbiotic associations, and to a lesser extent, parasitoid communities were stable over time and structured mainly by the A. pisum biotypes, the parasitoid pressure strongly varied during the season and differed among the three biotypes. This suggests a limited influence of parasitoid pressure on the dynamics of facultative endosymbionts at a seasonal scale. However, we found a positive correlation between the α and β diversities of the endosymbiont and parasitoid communities, indicating interactions between these two guilds. Also, we revealed a negative correlation between the prevalence of H. defensa and Fukatsuia symbiotica in co-infection and the intensity of parasitoid pressure in the alfalfa biotype, confirming in field conditions the protective effect of this symbiotic combination.

Published
2021
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3. Bacterial Community Diversity Harboured by Interacting Species.

Author

Mikaël Bili, Anne Marie Cortesero, Christophe Mougel, Jean Pierre Gauthier, Gwennola Ermel, Jean Christophe Simon, Yannick Outreman, Sébastien Terrat, Frédérique Mahéo, and Denis Poinsot

Subjects
Medicine, Science
Abstract

All animals are infected by microbial partners that can be passengers or residents and influence many biological traits of their hosts. Even if important factors that structure the composition and abundance of microbial communities within and among host individuals have been recently described, such as diet, developmental stage or phylogeny, few studies have conducted cross-taxonomic comparisons, especially on host species related by trophic relationships. Here, we describe and compare the microbial communities associated with the cabbage root fly Delia radicum and its three major parasitoids: the two staphylinid beetles Aleochara bilineata and A. bipustulata and the hymenopteran parasitoid Trybliographa rapae. For each species, two populations from Western France were sampled and microbial communities were described through culture independent methods (454 pyrosequencing). Each sample harbored at least 59 to 261 different bacterial phylotypes but was strongly dominated by one or two. Microbial communities differed markedly in terms of composition and abundance, being mainly influenced by phylogenetic proximity but also geography to a minor extent. Surprisingly, despite their strong trophic interaction, parasitoids shared a very low proportion of microbial partners with their insect host. Three vertically transmitted symbionts from the genus Wolbachia, Rickettsia, and Spiroplasma were found in this study. Among them, Wolbachia and Spiroplasma were found in both the cabbage fly and at least one of its parasitoids, which could result from horizontal transfers through trophic interactions. Phylogenetic analysis showed that this hypothesis may explain some but not all cases. More work is needed to understand the dynamics of symbiotic associations within trophic network and the effect of these bacterial communities on the fitness of their hosts.

Published
2016
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4. Genetic control of contagious asexuality in the pea aphid.

Author

Julie Jaquiéry, Solenn Stoeckel, Chloé Larose, Pierre Nouhaud, Claude Rispe, Lucie Mieuzet, Joël Bonhomme, Frédérique Mahéo, Fabrice Legeai, Jean-Pierre Gauthier, Nathalie Prunier-Leterme, Denis Tagu, and Jean-Christophe Simon

Subjects
Genetics, QH426-470
Abstract

Although evolutionary transitions from sexual to asexual reproduction are frequent in eukaryotes, the genetic bases of such shifts toward asexuality remain largely unknown. We addressed this issue in an aphid species where both sexual and obligate asexual lineages coexist in natural populations. These sexual and asexual lineages may occasionally interbreed because some asexual lineages maintain a residual production of males potentially able to mate with the females produced by sexual lineages. Hence, this species is an ideal model to study the genetic basis of the loss of sexual reproduction with quantitative genetic and population genomic approaches. Our analysis of the co-segregation of ∼ 300 molecular markers and reproductive phenotype in experimental crosses pinpointed an X-linked region controlling obligate asexuality, this state of character being recessive. A population genetic analysis (>400-marker genome scan) on wild sexual and asexual genotypes from geographically distant populations under divergent selection for reproductive strategies detected a strong signature of divergent selection in the genomic region identified by the experimental crosses. These population genetic data confirm the implication of the candidate region in the control of reproductive mode in wild populations originating from 700 km apart. Patterns of genetic differentiation along chromosomes suggest bidirectional gene flow between populations with distinct reproductive modes, supporting contagious asexuality as a prevailing route to permanent parthenogenesis in pea aphids. This genetic system provides new insights into the mechanisms of coexistence of sexual and asexual aphid lineages.

Published
2014
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5. Evolutionary consequences of loss of sexual reproduction on male-related traits in parthenogenetic lineages of the pea aphid

Author

Hélène Defendini, Maud Rimbault, Frédérique Mahéo, Romuald Cloteau, Gaëtan Denis, Lucie Mieuzet, Yannick Outreman, Jean‐Christophe Simon, Julie Jaquiéry, Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Université de Rennes (UR)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro Rennes Angers, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), French Research Agency (ANR). Grant Numbers: ANR-09-GENM-017-001, ANR-11-BSV7-005-01 INRAE-SPE Department Région Bretagne, ANR-09-GENM-0017,GW-Aphid,Génomique et transcriptomique des populations pour l'identification de gènes contrôlant la variation du mode reproducteur chez le puceron du pois(2009), and ANR-11-BSV7-0005,SPECIAPHID,Génétique de l'adaptation trophique et mécanismes d'isolement reproducteur chez les pucerons(2011)

Subjects
reproductive success, [SDE]Environmental Sciences, Genetics, clonal evolution, relaxed selection, male sexual traits, trait decay, Ecology, Evolution, Behavior and Systematics, loss of sexuality
Abstract

International audience; Transition from sexual reproduction to parthenogenesis constitutes a major life-history change with deep evolutionary consequences for sex-related traits, which are expected to decay. The pea aphid Acyrthosiphon pisum shows intraspecific reproductive polymorphism, with cold-resistant cyclically parthenogenetic (CP) lineages that alternate sexual and asexual generations and cold-sensitive obligately parthenogenetic (OP) lineages that produce only asexual females but still males. Here, the genotyping of 219 pea aphid lineages collected in cold-winter and mild-winter regions revealed contrasting population structures. Samples from cold-winter regions consisted mostly of distinct multilocus genotypes (MLGs) usually represented by a single sample (101 different MLGs for 111 samples) and were all phenotyped as CP. In contrast, fewer MLGs were found in mild-winter regions (28 MLGs for 108 samples), all but one being OP. Since the males produced by OP lineages are unlikely to pass on their genes (sexual females being rare in mild-winter regions), we tested the hypothesis that their traits could degenerate due to lack of selection by comparing male production and male reproductive success between OP and CP lineages. Male production was indeed reduced in OP lineages, but a less clear pattern was observed for male reproductive success: females mated with OP males laid fewer eggs (fertilized or not) but OP and CP males fertilized the same proportion of eggs. These differences may stem from the type of selective forces: male production may be counter-selected whereas male performances may evolve under the slower process of relaxed selection. The overall effective reproductive capacity of OP males could result from recent sex loss in OP lineages or underestimated reproductive opportunities.

Published
2023
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6. Signatures of genetic bottleneck and differentiation after the introduction of an exotic parasitoid for classical biological control

Author

Francisca Zepeda-Paulo, Jean-Christophe Simon, Frédérique Mahéo, Yannick Outreman, Blas Lavandero, Emilie Dion, Christian C. Figueroa, Universidad de Talca, Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST, 1110341, FONDECYT, PhD fellowship, CONICYT, AUS 0703, MECESUP, Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), AGROCAMPUS OUEST-Université de Rennes 1 (UR1), and Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National de la Recherche Agronomique (INRA)

Subjects
aphidius ervi, 0106 biological sciences, 0301 basic medicine, Conservation genetics, Biology, 010603 evolutionary biology, 01 natural sciences, Aphid parasitoids, 03 medical and health sciences, Genetic drift, Effective population size, Genetic variation, Genetic bottleneck, Biological invasions, introduction d'auxiliaire, Classic biological control, Ecology, Evolution, Behavior and Systematics, Genetic diversity, Ecology, insecte parasitoide, chili, genêtic variation, 030104 developmental biology, Population bottleneck, Genetic marker, diversité génétique, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Inbreeding, contrôle biologique
Abstract

International audience; As biological invasions, intentional introductions often result in a loss of genetic diversity in the new founder populations. In classical biological control programs, natural enemies introduced into novel environments are likely to suffer from population bottlenecks. Unlike invasive populations, individuals for biological control are typically kept in quarantine during several generations before being released in the field. This procedure reduces further the effective population size of the introduced populations, which thus increases the effects of inbreeding and genetic drift, resulting in a greater loss of genetic diversity. This study addresses the genetic consequences of the introduction of the parasitoid wasp Aphidius ervi, a successful biocontrol agent of important aphid target-pests in Chile. This was assessed by examining the genetic diversity and differentiation at nuclear and mitochondrial genetic markers in terms of (1) the magnitude of the genetic diversity loss after 38 years of the introduction of A. ervi, (2) the current level of genetic differentiation between Chilean introduced populations and putative native populations from France, and (3) the genetic relationships and magnitude of the genetic diversity loss between introduced populations of A. ervi in Chile compared to those introduced in North America. The results provide evidence that parasitoid populations suffered the effects of a moderate genetic bottleneck during the introduction, showing further a strong geographical genetic differentiation between populations in the natal and novel environments. In addition mtDNA sequences analysis showed evidence of a single main event of introduction in Chile, unlike the North American situation, where there is evidence for multiple introductions. The significance of the loss of genetic diversity during introductions related to the success of parasitoids as biocontrol agents in classical biological control programs is discussed.

Published
2015
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7. Inheritance patterns of secondary symbionts during sexual reproduction of pea aphid biotypes

Author

Manon de la Huerta, Frédérique Mahéo, Olivier Cosson, Jean Peccoud, Jean-Christophe Simon, and Joël Bonhomme

Subjects
0106 biological sciences, animal structures, Zoology, Hamiltonella defensa, 010603 evolutionary biology, 01 natural sciences, General Biochemistry, Genetics and Molecular Biology, 03 medical and health sciences, Botany, Inheritance Patterns, Paternal Inheritance, Ecology, Evolution, Behavior and Systematics, 030304 developmental biology, 0303 health sciences, Aphid, biology, Host (biology), fungi, food and beverages, biochemical phenomena, metabolism, and nutrition, biology.organism_classification, Acyrthosiphon pisum, Sexual reproduction, Insect Science, bacteria, Buchnera, Agronomy and Crop Science
Abstract

Herbivorous insects frequently harbor bacterial symbionts that affect their ecology and evolution. Aphids host the obligatory endosymbiont Buchnera, which is required for reproduction, together with facultative symbionts whose frequencies vary across aphid populations. These maternally transmitted secondary symbionts have been particularly studied in the pea aphid, Acyrthosiphon pisum, which harbors at least 8 distinct bacterial species (not counting Buchnera) having environmentally dependent effects on host fitness. In particular, these symbiont species are associated with pea aphid populations feeding on specific plants. Although they are maternally inherited, these bacteria are occasionally transferred across insect lineages. One mechanism of such nonmaternal transfer is paternal transmission to the progeny during sexual reproduction. To date, transmission of secondary symbionts during sexual reproduction of aphids has been investigated in only a handful of aphid lineages and 3 symbiont species. To better characterize this process, we investigated inheritance patterns of 7 symbiont species during sexual reproduction of pea aphids through a crossing experiment involving 49 clones belonging to 9 host-specialized biotypes, and 117 crosses. Symbiont species in the progeny were detected with diagnostic qualitative PCR at the fundatrix stage hatching from eggs and in later parthenogenetic generations. We found no confirmed case of paternal transmission of symbionts to the progeny, and we observed that maternal transmission of a particular symbiont species (Serratia symbiotica) was quite inefficient. We discuss these observations in respect to the ecology of the pea aphid.

Published
2013
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8. Bacterial community diversity harboured by interacting species

Author

Christophe Mougel, Jean-Pierre Gauthier, Frédérique Mahéo, Sébastien Terrat, Yannick Outreman, Jean Simon, Mikaël Bili, Anne Marie Cortesero, Denis Poinsot, Gwennola Ermel, Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST, Université de Rennes (UR), Agroécologie [Dijon], Institut National de la Recherche Agronomique (INRA)-Université de Bourgogne (UB)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement, Institut de Génétique, Environnement et Protection des Plantes ( IGEPP ), Institut National de la Recherche Agronomique ( INRA ) -Université de Rennes 1 ( UR1 ), Université de Rennes ( UNIV-RENNES ) -Université de Rennes ( UNIV-RENNES ) -AGROCAMPUS OUEST, Microbiologie : Risques Infectieux, Université de Rennes 1 ( UR1 ), Université de Rennes ( UNIV-RENNES ) -Université de Rennes ( UNIV-RENNES ) -CHU Pontchaillou [Rennes]-Faculté de Chirurgie Dentaire de Rennes-Faculté d'Odontologie-Structure Fédérative de Recherche en Biologie et Santé de Rennes ( Biosit : Biologie - Santé - Innovation Technologique ), Institut National de la Recherche Agronomique ( INRA ) -Université de Bourgogne ( UB ) -AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement, AGROCAMPUS OUEST-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National de la Recherche Agronomique (INRA), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-CHU Pontchaillou [Rennes]-Faculté de Chirurgie Dentaire de Rennes-Faculté d'Odontologie-Structure Fédérative de Recherche en Biologie et Santé de Rennes ( Biosit : Biologie - Santé - Innovation Technologique ), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), and Université de Rennes (UNIV-RENNES)

Subjects
0301 basic medicine, [SDV]Life Sciences [q-bio], lcsh:Medicine, species, Artificial Gene Amplification and Extension, Pathogenesis, Pathology and Laboratory Medicine, phylogeny, cabbage, genus, Polymerase Chain Reaction, geography, Parasitoid, Abundance (ecology), [ SDV.MP ] Life Sciences [q-bio]/Microbiology and Parasitology, Medicine and Health Sciences, Rickettsia, lcsh:Science, Trophic level, Multidisciplinary, biology, Ecology, Microbiota, beetle, Genomics, Biodiversity, Bacterial Pathogens, Insects, Coleoptera, symbiont, [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology, pyrosequencing, Medical Microbiology, Host-Pathogen Interactions, [SDE]Environmental Sciences, Wolbachia, France, Pathogens, microbial community, Research Article, Arthropoda, Spiroplasma, Mollicutes, Microbial Genomics, Research and Analysis Methods, Microbiology, 03 medical and health sciences, Phylogenetics, Genetics, Animals, [SDV.BV]Life Sciences [q-bio]/Vegetal Biology, Molecular Biology Techniques, Molecular Biology, Microbial Pathogens, parasitoid, Bacteria, Host (biology), Diptera, lcsh:R, fungi, Organisms, Biology and Life Sciences, biology.organism_classification, Invertebrates, Hymenoptera, 030104 developmental biology, lcsh:Q, Microbiome, Delia radicum
Abstract

International audience; All animals are infected by microbial partners that can be passengers or residents and influence many biological traits of their hosts. Even if important factors that structure the composition and abundance of microbial communities within and among host individuals have been recently described, such as diet, developmental stage or phylogeny, few studies have conducted cross-taxonomic comparisons, especially on host species related by trophic relationships. Here, we describe and compare the microbial communities associated with the cabbage root fly Delia radicum and its three major parasitoids: the two staphylinid beetles Aleochara bilineata and A. bipustulata and the hymenopteran parasitoid Trybliographa rapae. For each species, two populations from Western France were sampled and microbial communities were described through culture independent methods (454 pyrosequencing). Each sample harbored at least 59 to 261 different bacterial phylotypes but was strongly dominated by one or two. Microbial communities differed markedly in terms of composition and abundance, being mainly influenced by phylogenetic proximity but also geography to a minor extent. Surprisingly, despite their strong trophic interaction, parasitoids shared a very low proportion of microbial partners with their insect host. Three vertically transmitted symbionts from the genus Wolbachia, Rickettsia, and Spiroplasma were found in this study. Among them, Wolbachia and Spiroplasma were found in both the cabbage fly and at least one of its parasitoids, which could result from horizontal transfers through trophic interactions. Phylogenetic analysis showed that this hypothesis may explain some but not all cases. More work is needed to understand the dynamics of symbiotic associations within trophic network and the effect of these bacterial communities on the fitness of their hosts. © 2016 Bili et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Published
2016
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9. Assessment of the Dominance Level of the R81T Target Resistance to Two Neonicotinoid Insecticides in[i] Myzus persicae[/i] (Hemiptera: Aphididae)

Author

Jean-Christophe Simon, Frédérique Mahéo, Lise Roy, Claire Mottet, Séverine Fontaine, Laëtitia Caddoux, Christine Brazier, Annie Micoud, Agence nationale de sécurité sanitaire de l'alimentation, de l'environnement et du travail (ANSES), Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, Centre d’Ecologie Fonctionnelle et Evolutive (CEFE), Institut de Recherche pour le Développement (IRD [France-Sud])-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE)-Université de Montpellier (UM)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Université Paul-Valéry - Montpellier 3 (UM3), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)-Université Paul-Valéry - Montpellier 3 (UPVM)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut de Recherche pour le Développement (IRD [France-Sud]), Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST, Université Paul-Valéry - Montpellier 3 (UPVM)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-École Pratique des Hautes Études (EPHE), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)

Subjects
0106 biological sciences, 0301 basic medicine, Insecticides, Genotype, Pyridines, Myzus persicae, Thiazines, 01 natural sciences, R81T mutation, Insecticide Resistance, resistance, Neonicotinoids, 03 medical and health sciences, chemistry.chemical_compound, Imidacloprid, Botany, Animals, Allele, ComputingMilieux_MISCELLANEOUS, Genetics, Aphid, Ecology, biology, Imidazoles, Neonicotinoid, neonicotinoid, Aphididae, General Medicine, Nitro Compounds, biology.organism_classification, Thiacloprid, dominance level, [SDV.BV.PEP]Life Sciences [q-bio]/Vegetal Biology/Phytopathology and phytopharmacy, 010602 entomology, 030104 developmental biology, chemistry, Aphids, Insect Science, Mutation, France
Abstract

International audience; Myzus persicae (Sulzer, 1776), a major crop pest worldwide, displays insecticide resistance to most molecules. The R81T substitution on the β1 subunit of nicotinic receptors of acetylcholine (nAChR) confers target site resistance to neonicotinoids and is widespread in aphid populations colonizing peach tree orchards in Southern Europe. But the impact of this resistance in the field, as well as ways to optimize its management, depends largely on the dominance level of the R81T mutation. In this study, we measured by in vitro assays the response of R81T mutation to two neonicotinoids (imidacloprid and thiacloprid) in 23 M. persicae clones with different resistance genotypes in order to assess the dominance status of this allele. In this study, all homozygous clones for the R81T mutation (genotype 81(TT)) showed a much higher level of resistance to both active substances than other clones. The heterozygous clones 81(RT) displayed a slightly higher level of resistance than wild homozygous, though resistance phenotypes against both neonicotinoids in these two genotypes were overlapping. A great variation of resistance level was found within these two latter clones' categories. The dominance level of insecticide resistance (DLC) strongly suggested that the mutant allele 81T is semirecessive (the wild 81R allele being rather dominant) for both insecticide molecules under test. Mean DLC values were 0.316 for imidacloprid and 0.351 for thiacloprid. Cross-resistance was shown between imidacloprid and thiacloprid. This partial recessivity is valuable information to broaden the knowledge on neonicotinoid resistance, a prerequisite for devising adapted management strategies against insecticide-resistant populations of M. persicae.

Published
2016
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10. Does sex-biased dispersal account for the lack of geographic and host-associated differentiation in introduced populations of an aphid parasitoid?

Author

Francisca Zepeda-Paulo, Emilie Dion, Christian C. Figueroa, Blas Lavandero, Yannick Outreman, Jean-Christophe Simon, Frédérique Mahéo, Universidad de Talca, Universidad Austral de Chile, Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, 1110341, Fondo Nacional de Desarrollo Científico y Tecnológico, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), and Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST

Subjects
[SDV.SA]Life Sciences [q-bio]/Agricultural sciences, media_common.quotation_subject, Aphidius ervi, Zoology, flux de gènes, Insect, host fidelity, interaction hôte parasitoïde, différenciation génétique, Parasitoid, Gene flow, Aphid parasitoids, genetic differentiation, sex-biased dispersal, spécificité de l'hôte, Ecology, Evolution, Behavior and Systematics, Nature and Landscape Conservation, media_common, Original Research, Aphid, Ecology, biology, Host (biology), insecte parasitoide, fungi, microsatellite loci, biology.organism_classification, Genetic differentiation, Agricultural sciences, sex-biased dispersal, Biological dispersal, genetic differentiation, sibship inference, Sciences agricoles
Abstract

International audience; Host recognition and use in female parasitoids strongly relies on host fidelity, a plastic behavior which can significantly restrict the host preferences of parasitoids, thus reducing the gene flow between parasitoid populations attacking different insect hosts. However, the effect of migrant males on the genetic differentiation of populations has been frequently ignored in parasitoids, despite its known impact on gene flow between populations. Hence, we studied the extent of gene flow mediated by female and male parasitoids by assessing sibship relationships among parasitoids within and between populations, and its impact on geographic and host-associated differentiation in the aphid parasitoid Aphidius ervi. We report evidences of a high gene flow among parasitoid populations on different aphid hosts and geographic locations. The high gene flow among parasitoid populations was found to be largely male mediated, suggested by significant differences in the distribution of full-sib and paternal half-sib dyads of parasitoid populations.

Published
2015
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11. Genetic characterisation of new host-specialised biotypes and novel associations with bacterial symbionts in the pea aphid complex

Author

Manon de la Huerta, Cindy Laurence, Jean-Christophe Simon, Jean Peccoud, Frédérique Mahéo, Ecologie, Evolution, Symbiose (EES), Ecologie et biologie des interactions (EBI), Université de Poitiers-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-Centre National de la Recherche Scientifique (CNRS), Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), ANR-11-BSV7-005-01, ANR-11-BSV7-0005,SPECIAPHID,Génétique de l'adaptation trophique et mécanismes d'isolement reproducteur chez les pucerons(2011), and Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST

Subjects
0106 biological sciences, Species complex, Hippocrepis, Population, Hamiltonella defensa, 010603 evolutionary biology, 01 natural sciences, microsatellites, 03 medical and health sciences, Botany, Hippocrepis comosa, genetic structure, ecological speciation, education, hybridization, insect-plant interactions, Ecology, Evolution, Behavior and Systematics, 030304 developmental biology, 0303 health sciences, Aphid, education.field_of_study, biology, Ecology, food and beverages, 15. Life on land, biochemical phenomena, metabolism, and nutrition, biology.organism_classification, Acyrthosiphon pisum, Genetic divergence, secondary endosymbionts, Insect Science, Aphids, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, gene flow
Abstract

International audience; 1. The pea aphid, Acyrthosiphon pisum Harris, constitutes a complex of sympatric populations that are specialised to distinct species of Fabaceae. So far, 12 such populations have been characterised genetically as genetic clusters associated with one or few legumes species. These clusters form a continuum of genetic divergence linking host-associated races, which show moderate hybridization, to nascent species. They are also known to be associated with different species of endosymbiotic bacteria, which have environmentally dependent effects on aphid fitness2. Here, we report on the genetic characterisation of new host-associated populations in this species complex. We sampled pea aphids in eastern France on Genista tinctoria, G. sagittalis, Onobrychis viciifolia, and Hippocrepis comosa. Bayesian clustering methods based on genotypes obtained at 25 microsatellite loci showed that each sampled plant species hosted a specific pea aphid population. Comparison with previously characterised biotypes showed that the population associated with Hippocrepis comosa was no different from that on Securigera varia. Migrant aphids from other host plants and hybrids were found at various frequencies on the newly sampled plant species. They were particularly frequent on Onobrychis viciifolia, occasional between the two Genista-associated populations, and rare on Hippocrepis comosa.3. PCR-based screening of bacterial species revealed new associations between aphid biotypes and facultative endosymbionts, chiefly the combination of Serratia symbiotica and Hamiltonella defensa within most individuals collected on Genista.4. The newly identified biotypes, which add up to a total of 15 within the pea aphid complex, offer new material to study the mechanisms and genetic bases of host-specialisation and ecological speciation in this model aphid.

Published
2015
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12. Genomic regions repeatedly involved in divergence among plant-specialized pea aphid biotypes

Author

Julie Jaquiéry, Frédérique Mahéo, Lucie Mieuzet, Jean Peccoud, Pierre Nouhaud, Jean-Christophe Simon, Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), INRA, Région Bretagne, Swiss National ScienceFoundation post-doc grants [PBLAA-122658, PA00P3-139720], INRA-AIP BioRessources, Fondation pour la Recherche sur la Biodiversité [AAP-IN-2009-020], ANR GW-Aphid [ANR-09-GENM-017-001], ANR Speciaphid [ANR-11-BSV7-005-01], ANR-11-BSV7-0005,SPECIAPHID,Génétique de l'adaptation trophique et mécanismes d'isolement reproducteur chez les pucerons(2011), and Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST

Subjects
0106 biological sciences, insect–plant interactions, Genetic Speciation, Genome, Insect, Genome Scan, 010603 evolutionary biology, 01 natural sciences, Ecological speciation, 03 medical and health sciences, Gene Frequency, Adaptive radiation, ecological speciation, Polymorphic Microsatellite Marker, Animals, parallel evolution, Ecology, Evolution, Behavior and Systematics, 030304 developmental biology, Genetics, Ecotype, 0303 health sciences, [SDV.GEN.GPO]Life Sciences [q-bio]/Genetics/Populations and Evolution [q-bio.PE], biology, Genetic Drift, food and beverages, outlier loci, Reproductive isolation, biology.organism_classification, Biological Evolution, Acyrthosiphon pisum, Aphids, Female, Adaptation, adaptive radiation, Neutral theory of molecular evolution, Microsatellite Repeats
Abstract

Understanding the genetic bases of biological diversification is a long-standing goal in evolutionary biology. Here, we investigate whether replicated cases of adaptive divergence involve the same genomic regions in the pea aphid, Acyrthosiphon pisum, a large complex of genetically differentiated biotypes, each specialized on different species of legumes. A previous study identified genomic regions putatively involved in host-plant adaptation and/ or reproductive isolation by performing a hierarchical genome scan in three biotypes. This led to the identification of 11 FST outliers among 390 polymorphic microsatellite markers. In this study, the outlier status of these 11 loci was assessed in eight biotypes specialized on other host plants. Four of the 11 previously identified outliers showed greater genetic differentiation among these additional biotypes than expected under the null hypothesis of neutral evolution (a < 0.01). Whether these hotspots of genomic divergence result from adaptive events, intrinsic barriers or reduced recombination is discussed.

Published
2014
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13. Genome scans reveal candidate regions involved in the adaptation to host plant in the pea aphid complex

Author

Renaud Vitalis, Fabrice Legeai, Solenn Stoeckel, Frédérique Mahéo, Bernard N, Bonvoisin A, Lucie Mieuzet, Julie Jaquiéry, Pierre Nouhaud, Jean-Christophe Simon, Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST, Scalable, Optimized and Parallel Algorithms for Genomics (GenScale), Inria Rennes – Bretagne Atlantique, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-GESTION DES DONNÉES ET DE LA CONNAISSANCE (IRISA-D7), Institut de Recherche en Informatique et Systèmes Aléatoires (IRISA), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-Institut National de Recherche en Informatique et en Automatique (Inria)-Télécom Bretagne-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-Institut National de Recherche en Informatique et en Automatique (Inria)-Télécom Bretagne-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche en Informatique et Systèmes Aléatoires (IRISA), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-Télécom Bretagne-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), Littoral, Environnement, Télédétection, Géomatique (LETG - Brest), Littoral, Environnement, Télédétection, Géomatique UMR 6554 (LETG), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Université d'Angers (UA)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Brest (UBO)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut de Géographie et d'Aménagement Régional de l'Université de Nantes (IGARUN), Université de Nantes (UN)-Université de Nantes (UN)-Université de Caen Normandie (UNICAEN), Université de Nantes (UN)-Université de Nantes (UN), Centre de Biologie pour la Gestion des Populations (UMR CBGP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Université de Montpellier (UM)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, GESTION DES DONNÉES ET DE LA CONNAISSANCE (IRISA-D7), Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Université de Bretagne Sud (UBS)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Rennes (ENS Rennes)-Institut National de Recherche en Informatique et en Automatique (Inria)-Télécom Bretagne-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-CentraleSupélec-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Université de Rennes (UNIV-RENNES)-CentraleSupélec-Institut de Recherche en Informatique et Systèmes Aléatoires (IRISA), Université de Rennes (UNIV-RENNES)-CentraleSupélec-Inria Rennes – Bretagne Atlantique, Institut National de Recherche en Informatique et en Automatique (Inria), Centre National de la Recherche Scientifique (CNRS)-Université de Rennes 2 (UR2), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Université de Brest (UBO)-École pratique des hautes études (EPHE)-Université de Nantes (UN)-Université d'Angers (UA)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes 2 (UR2), Normandie Université (NU)-Normandie Université (NU), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), CentraleSupélec-Télécom Bretagne-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National de Recherche en Informatique et en Automatique (Inria)-École normale supérieure - Rennes (ENS Rennes)-Université de Bretagne Sud (UBS)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Télécom Bretagne-Université de Rennes 1 (UR1), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Institut de Recherche en Informatique et Systèmes Aléatoires (IRISA), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-École normale supérieure - Rennes (ENS Rennes)-Université de Bretagne Sud (UBS)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), Normandie Université (NU)-Normandie Université (NU)-Université d'Angers (UA)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Brest (UBO)-Université de Rennes 2 (UR2), and Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Géographie et d'Aménagement Régional de l'Université de Nantes (IGARUN)

Subjects
0106 biological sciences, Candidate gene, Genotype, Genetic Speciation, Population, Genome, Insect, interaction plante insecte, Adaptation, Biological, adaptation, Biology, plante hôte, acyrthosiphon pisum, 010603 evolutionary biology, 01 natural sciences, Genome, Ecological speciation, 03 medical and health sciences, analyse de génome, Genetics, Animals, Selection, Genetic, education, Ecology, Evolution, Behavior and Systematics, 030304 developmental biology, 0303 health sciences, education.field_of_study, Vegetal Biology, Peas, food and beverages, Sequence Analysis, DNA, légume, [SDV.BIBS]Life Sciences [q-bio]/Quantitative Methods [q-bio.QM], Genetic divergence, spéciation, Sympatric speciation, puceron, Aphids, Adaptation, [INFO.INFO-BI]Computer Science [cs]/Bioinformatics [q-bio.QM], Neutral theory of molecular evolution, Biologie végétale, Microsatellite Repeats, divergence génétique
Abstract

Publication Inra prise en compte dans l'analyse bibliométrique des publications scientifiques mondiales sur les Fruits, les Légumes et la Pomme de terre. Période 2000-2012. http://prodinra.inra.fr/record/256699; International audience; A major goal in evolutionary biology is to uncover the genetic basis of adaptation. Divergent selection exerted on ecological traits may result in adaptive population differentiation and reproductive isolation and affect differentially the level of genetic divergence along the genome. Genome-wide scan of large sets of individuals from multiple populations is a powerful approach to identify loci or genomic regions under ecologically divergent selection. Here, we focused on the pea aphid, a species complex of divergent host races, to explore the organization of the genomic divergence associated with host plant adaptation and ecological speciation. We analysed 390 microsatellite markers located at variable distances from predicted genes in replicate samples of sympatric populations of the pea aphid collected on alfalfa, red clover and pea, which correspond to three common host-adapted races reported in this species complex. Using a method that accounts for the hierarchical structure of our data set, we found a set of 11 outlier loci that show higher genetic differentiation between host races than expected under the null hypothesis of neutral evolution. Two of the outliers are close to olfactory receptor genes and three other nearby genes encoding salivary proteins. The remaining outliers are located in regions with genes of unknown functions, or which functions are unlikely to be involved in interactions with the host plant. This study reveals genetic signatures of divergent selection across the genome and provides an inventory of candidate genes responsible for plant specialization in the pea aphid, thereby setting the stage for future functional studies.

Published
2012
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14. The genetics of obligate parthenogenesis in an aphid species and its consequences for the maintenance of alternative reproductive modes

Author

Jean-Christophe Simon, Frédérique Mahéo, Jean Francois Le Gallic, Charles-Antoine Dedryver, F. Dedryver, Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), AGROCAMPUS OUEST-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National de la Recherche Agronomique (INRA), and Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST

Subjects
0106 biological sciences, Male, RHOPALOSIPHUM-PADI, [SDV]Life Sciences [q-bio], Parthenogenesis, 01 natural sciences, DAPHNIA-PULEX, Sitobion avenae, oligogenic inheritance, suppressor gene, Genetics (clinical), Genetics, 0303 health sciences, Aphid, biology, MYZUS-PERSICAE SULZ, Homozygote, ASEXUAL POPULATIONS, food and beverages, Oligogenic Inheritance, Phenotype, Female, Original Article, obligate parthenogenesis, Seasons, aphid clones, Locus (genetics), 010603 evolutionary biology, Asexuality, 03 medical and health sciences, Animals, Allele, SEASONAL PHOTOPERIODISM, 030304 developmental biology, GENERAL-PURPOSE GENOTYPES, cyclical parthenogenesis, Obligate, Models, Genetic, MICROSATELLITE MARKERS, Genetic Variation, biology.organism_classification, SITOBION-AVENAE, LIFE-CYCLE, sexuality, DROSOPHILA-MELANOGASTER, Genetic Loci, Aphids, Microsatellite Repeats
Abstract

International audience; Although loss of sex is widespread among metazoans, the genetic mechanisms underlying the transition to asexuality are poorly understood. Aphids are good models to address this issue because they frequently show reproductive-mode variation at the species level, involving cyclical parthenogens (CP) that reproduce sexually once a year and obligate parthenogens (OP) that reproduce asexually all year round. Here, we explore the genetic basis of OP in the cereal aphid Sitobion avenae by crossing several genotypes with contrasting reproductive modes and then characterising the reproductive phenotypes of F1 and F2 offspring. The analysis of phenotypic variation in F1 and F2 progenies suggests that at least two autosomal loci control OP in S. avenae. First, the transition to asexuality seems to depend on a single recessive locus, because the offspring from self-crossed cyclical parthenogenetic genotypes contain either 0 or 25% OP. Second, as we observed OP in the F1 progenies from crosses between CP and OP, and some CP in the offspring from outcrossed OP, a dominant 'suppressor' gene may also be involved, being inactive when in a recessive homozygous state in CP; this is the most parsimonious explanation for these results. This oligogenic inheritance of OP in S. avenae appears to be an efficient genetic system to generate new OP genotypes continually. It also allows asexuality-inducing alleles to be protected locally during harsh winters when extreme frost kills most OP, and then to spread very quickly after winter. Heredity (2013) 110, 39-45; doi:10.1038/hdy.2012.57; published online 19 September 2012

Published
2012
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