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Qui sommes-nous ?

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-05595327] Poly-immunity arrays associated with Rhs toxins confer wide protection against competitors

    Bacterial genomes evolve under intense competition with diverse microorganisms. Polymorphic toxins are one of the best examples for demonstrating the intensity of this process. They comprise hypervariable C-terminal domains, encoding a broad range of toxic activities. These toxins are typically accompanied by highly specific immunity proteins encoded immediately downstream, which protect the producing bacteria from self-intoxication or fratricide. Here, we show that Photorhabdus and Xenorhabdus spp. genomes harbor extensive arrays of clustered immunity genes encoding proteins that neutralize type VI secretion system (T6SS) rearrangement hot spot (Rhs) polymorphic toxins secreted by closely related species. These immunity genes derive from ancient toxin-immunity pairs, yet only the immunity components are conserved, highlighting their protective role. Consistent with this, many of these immunity genes are expressed under steady-state conditions. Finally, we identify novel genetic elements conserved in several bacterial genera, termed Xer passenger cassettes (XPCs), which associate with both Rhs and the contact-dependent growth inhibition (CDI) polymorphic toxins, suggesting a potential role in their diversification and horizontal dissemination.

    ano.nymous@ccsd.cnrs.fr.invalid (Julius Martinkus) 17 Apr 2026

    https://hal.science/hal-05595327v1
  • [hal-05534918] Is the extreme within-population genome size variation real in Spodoptera frugiperda?

    Genome size variation is one of the main topics in evolutionary genomics. Recent studies in Spodoptera frugiperda (Insect; Lepidoptera) reported very striking results, including large genome size differences, up to a twofold variation within populations, with the existence of 1.37 Gb of non-reference genome sequences, which is 2.5 times larger than the reference genome, 544 Mb in size. These reports raise the question of whether such extreme genome size variations within populations can be biologically realistic. To evaluate these results, we analyzed reference genome assemblies and resequencing datasets from multiple independent studies, including those from the original research. We observed that high-quality reference genomes consistently range from 380 Mb to 390 Mb, aligning closely with flow cytometry measurements. The genome size estimates using k-mer-based approaches from field-collected samples across four independent studies suggest that extensive genome size variation within S. frugiperda is unlikely to occur. Additionally, genome size appears to have remained stable for at least 15.89 million years in the ancestral lineage of S. frugiperda . Taken together, these results do not support the existence of extreme genome size variation in S. frugiperda , emphasizing the need for careful validation.

    ano.nymous@ccsd.cnrs.fr.invalid (Karine Durand) 03 Mar 2026

    https://hal.inrae.fr/hal-05534918v1
  • [hal-05155756] Characterization of the genomic sequence of an iflavirus, a protoambidensovirus, and of three microviruses detected in mosquitoes (Aedes albopictus and Culex quinquefasciatus)

    We report the complete CDS of five viruses: XiangYun picorna-like virus 4 ( Iflaviridae ), Protoambidensovirus dipteran1 ( Parvoviridae ), and three microviruses ( Microviridae ), detected by viromics surveillance of Aedes albopictus and Culex quinquefasciatus from Réunion Island. The protoambidensovirus detected in A. albopictus belongs to a clade previously reported only in Culex pipiens.

    ano.nymous@ccsd.cnrs.fr.invalid (Sarah François) 13 Mar 2026

    https://hal.inrae.fr/hal-05155756v1
article

16 avril 2026

Rédaction : A-N. Volkoff, S. Gaudriaut, 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.