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DGIMI est une unité mixte de recherche ayant pour tutelles INRAE et l'Université de Montpellier. Elle est située sur le campus Triolet de l'Université de Montpellier et accueille une trentaine de personnels INRAE et UM.

Les recherches développées dans l'UMR DGIMI visent à mieux comprendre les interactions entre les insectes et leur environnement biotique et abiotique dans les agrosystèmes, selon deux axes thématiques 

HAL : Dernières publications

  • [hal-05727261] Differences in mainland–island genetic diversity in two moths suggest species-specific outcomes

    Genetic divergence along elevational gradients between mainland and island populations provides an opportunity to test the island genetic erosion model, which predicts reduced genetic diversity and increased differentiation in island populations. We examined two moth species, a geometrid moth ( Alcis angulifera ) and an erebid moth ( Hydrillodes morosa ), sampled along elevational gradients on Mt. Jirisan (mainland) and Mt. Hallasan (island) in southern South Korea. A total of 155 individuals were analyzed using mitochondrial cytochrome oxidase subunit I (mt COI) sequences. We identified 61 haplotypes across both species. A. angulifera exhibited similarly high genetic diversity on the mainland and island, whereas H. morosa showed overall lower diversity relative to A. angulifera but pronounced regional differences, with significantly higher haplotype and nucleotide diversity on the island. Mantel tests revealed significant genetic divergence between mainland and island populations but not within individual mountains, suggesting ongoing gene flow within elevational gradients. AMOVA indicated moderate differentiation in A. angulifera (F CT = 0.08) and stronger differentiation in H. morosa (F CT = 0.14), with most genetic variation occurring within populations. Gene flow estimates further highlighted contrasting patterns, with high connectivity in A. angulifera (Nm = 5.49) and restricted migration in H. morosa (Nm = 0.08). Together, these results indicate that while A. angulifera maintains genetic cohesion across regions, H. morosa exhibits stronger geographic and elevational structuring due to limited gene flow. Our findings do not support a universal reduction in genetic diversity in island populations; instead, they highlight the importance of species-specific ecological traits and geographic context in shaping genetic diversity patterns, suggesting that the island genetic-erosion pattern is more context-dependent than previously appreciated.

    ano.nymous@ccsd.cnrs.fr.invalid (Sei-Woong Choi) 26 Aug 2026

    https://hal.science/hal-05727261v1
  • [hal-05669785] Investigating the Genetic Underpinnings of Ongoing Fall Armyworm ( FAW ) Range Expansion in Aotearoa New Zealand

    Spodoptera frugiperda (fall armyworm; FAW) is a major agricultural pest native to the Americas, with the first reported invasion of Africa in early 2016. Since then, FAW has spread rapidly across Africa and Asia before invading Australia (2020) and first being detected in Aotearoa New Zealand in February 2022. Here, we assessed the whole genomes of 34 novel FAW individuals along the invasion front (representing three new invasive populations from Cambodia, Australia, and New Zealand) with the largest publicly available global FAW genome dataset ( n = 173), resulting in a dataset of 112 and 99 samples from the invasive and native range, respectively, to: (1) place the new invasive populations within the global invasion; (2) identify the potential geographic origin of the New Zealand invasion, including from a single or multiple incursion event; and (3) assess pre‐existing insecticide resistance potential at the invasion front. We confirm that these new invasions conform to the broad population structure of the initial invasive populations identified in Benin (West Africa), all of which belong to the invasive corn strain, as defined through previous triosephosphate isomerase (TPI) analysis and associated isolation from specific host plants. While we could not confidently assign the source population of the New Zealand invasion, we find preliminary support for a multiple introduction hypothesis in our data, which could contribute to increased genetic diversity within the New Zealand population. Further sampling is therefore required to fully characterise the origins of the New Zealand invasion. In novel samples, we detected putative insecticide resistance alleles previously reported in other invasive populations. These resistant loci should be tracked over time to understand the mechanisms enabling the invasion success of FAW in the Asia‐Pacific region. We emphasise that sharing of genomic resources between institutions and consortia is an essential first step in the control of this global invader.

    ano.nymous@ccsd.cnrs.fr.invalid (Amy Vaughan) 25 Jun 2026

    https://hal.science/hal-05669785v1
  • [hal-05651879] Argonaute protein and small RNA expression patterns in Spodoptera frugiperda (Lepidoptera, Noctuidae)

    PIWI-interacting RNAs (piRNAs) and PIWI proteins were initially described as playing a role in gametogenesis and maintaining genome integrity by controlling transposable elements (TEs). Expressed also in the soma and able to regulate protein coding gene expression, they are involved in multiple biological pathways, including host-pathogens interaction, sex determination and reproductive isolation. Spodoptera frugiperda (Sf) is a major invasive insect pest species consisting of two strains with distinct host-plant ranges. To identify which pathway was regulated by piRNAs in this species, we characterized proteins and genomic regions involved in their biogenesis, as well as TE and gene transcripts regulated. By phylogenetic analysis, we identified two new Piwi genes conserved in the genus Spodoptera, compared to the Lepidopteran model Bombyx mori, one more than in Drosophila. One of them, more expressed in the gonads than in the soma, could be a functional homolog of Drosophila PIWI or replace AGO3. A pool of 11 sRNA-Seq libraries was used to annotate piRNA clusters with ShortStack in the genomes of the two Sf strains. Identification of TE targeted by putative piRNAs revealed that active transposons may differ between the two Sf strains, despite a similar TE content, as a putative cause or consequence of reproductive isolation. GO analysis of genes targeted by piRNAs shows that some are involved in protein translation initiation. A piRNA cluster in the Masc gene suggests that sex determination is regulated by piRNAs. Our analysis contributes to functional annotation of the Sf strains genomes and supports additional roles than silencing of transposable elements for piRNAs.

    ano.nymous@ccsd.cnrs.fr.invalid (Imène Séninet) 10 Jun 2026

    https://hal.science/hal-05651879v1
article

31 juillet 2026

Rédaction : A-N. Volkoff, S. Gaudriault, A-S Gosselin-Grenet, I. Seninet

« RAVAGÉS »

« Une conférence théâtralisée pour sauver ta culture »

Dans le cadre du concours doctoral 2026 de l’école doctorale GAIA, DGIMI propose plusieurs sujets de thèse. N’hésitez pas à contacter les encadrants si vous souhaitez candidater.

Logo UM

Dans le cadre du projet interdisciplinaire microbiologie/chimie "MetaboNEP: Exploration métabolomique et fonctionnelle des bactéries associées aux nématodes entomopathogènes: vers de nouveaux métabolites pour le biocontrôle et l’écologie microbienne", sont proposés à l'université de Montpellier (collaboration DGIMI/IBMM).

Sigle INRAe

Nous recherchons tout particulièrement à renforcer notre expertise sur le rôle des éléments transposables (ET) ou des éléments viraux endogènes (EVE) dans l’évolution et l’adaptation des génomes d’insectes.