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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 

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HAL : Dernières publications

  • [hal-04122847] Convergent origin and accelerated evolution of vesicle-associated RhoGAP proteins in two unrelated parasitoid wasps

    Animal venoms and other protein-based secretions that perform a variety of functions, from predation to defense, are highly complex cocktails of bioactive compounds. Gene duplication, accompanied by modification of the expression and/or function of one of the duplicates under the action of positive selection, followed by further duplication to produce multigene families of toxins is a well-documented process in venomous animals. This evolutionary model has been less described in parasitoid wasps, which use maternal fluids, including venom, to protect their eggs from encapsulation by the host immune system. Here, we evidence the convergent recruitment and accelerated evolution of two multigene families of RhoGAPs presumably involved in virulence in two unrelated parasitoid wasp species, Leptopilina boulardi (Figitidae) and Venturia canescens (Icheumonidae). In both species, these RhoGAPs are associated with vesicles that act as transport systems to deliver virulence factors, but are produced in different tissues: the venom gland in Leptopilina sp. and the ovarian calyx in V. canescens. We show that the gene encoding the cellular RacGAP1 is at the origin of the virulent RhoGAP families found in Leptopilina sp. and V. canescens. We also show that both RhoGAP families have undergone evolution under positive selection and that almost all of these RhoGAPs lost their GAP activity and GTPase binding ability due to mutations in key amino acids. These results suggest an accelerated evolution and functional diversification of these vesicle-associated RhoGAPs in the two phylogenetically distant parasitoid species. The potential new function(s) and the exact mechanism of action of these proteins in host cells remain to be elucidated.

    ano.nymous@ccsd.cnrs.fr.invalid (Dominique Colinet) 13 Oct 2026

    https://hal.inrae.fr/hal-04122847v1
  • [hal-05778778] Selective manipulation of the host RNA-polymerase transcription fidelity increases phenotypic mutations in an insect Parvovirus

    In the dynamic dance of evolution, organisms are often faced with fluctuating environments to which adaptation through selection of traditional heritable genetic mutations can be limiting. In this study, we unveil a refined mechanism of non-heritable variability in a virus with a compact DNA genome. We discovered that the genome of the Junona cœnia densovirus (JcDV) experiences a 10-fold lower transcription fidelity than the rest of the host’s transcriptome, despite the shared transcription machinery. We found that the virus’ capsid proteins interact with the host’s RNA Polymerase II, and further show that truncating these proteins through early stop codons largely restore the transcriptional fidelity of viral genes. These observations suggest a potential mechanism for the selective manipulation of transcription accuracy. We also pinpoint specific sequence contexts that may provide other knobs to finely control the local transcription fidelity. We estimate that this lower transcriptional fidelity results in more than 7% of the viral proteome bearing at least one non-synonymous mutation. The production of non-heritable functional diversity by hijacking the transcriptional machinery might be a refined strategy to enhance short term adaptation within the complex and ever-changing host-parasite interface, and might be shared by other genetic parasites. Our findings shed light on a virus-specific transcription fidelity control mechanism, expanding our understanding of adaptive strategies in biological entities.

    ano.nymous@ccsd.cnrs.fr.invalid (Thomas Labadie) 05 Oct 2026

    https://hal.inrae.fr/hal-05778778v1
  • [hal-05780447] Population Genomics Analysis to Reveal Evolutionary Dynamics of Fall Armyworm Global Invasion

    [...]

    ano.nymous@ccsd.cnrs.fr.invalid (Kiwoong Nam) 06 Oct 2026

    https://hal.inrae.fr/hal-05780447v1

Actualités

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événement Du 03 oct. 2026 au 04 oct. 2026 Village des sciences de Montpellier

Fête de la science 2026

Pour cette édition 2026, le laboratoire DGIMI vous propose une animation sur la thématique "Insectes, plantes, vers, microbes : qui mange qui ?".
24 11
24 novembre 2026 Agropolis International - 1000, av. Agropolis, 34090 Montpellier

Journée scientifique du Vectopole Sud

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Cette année les présentations auront pour thématique "Le rôle des hôtes secondaires et des réservoirs (plantes, faune sauvage ou domestique) dans l'épidémiologie et la gestion des vecteurs et des ravageurs"

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