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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-05473549] Four nudivirus core genes present in the genome of Venturia canescens are required for virus-like particle formation and prevention of encapsulation of parasitoid wasp eggs

    ABSTRACT Venturia canescens is a parasitoid wasp that harbors a domesticated endogenous virus (DEV) and parasitizes host insects like Ephestia kuehniella . The V. canescens DEV evolved from an alphanudivirus and produces virus-like particles (VLPs) in females that protect wasp eggs from a host immune defense called encapsulation. In contrast, very few DEV genes required for VLP formation and function have been identified. In this study, we characterized five V. canescens DEV genes of unknown function that all nudiviruses encode. Three of these genes are single copy ( OrNVorf18-like , OrNVorf61-like , and OrNVorf76-like ), while OrNVorf41-like has expanded into a six-member family and OrNVorf47-like has expanded into a three-member family. Sequence analysis indicated all of these genes retain essential motifs present in nudivirus homologs, while transmission electron microscopy (TEM) studies characterized the timing of VLP formation during the wasp pupal stage. RNA interference (RNAi) assays identified OrNVorf18-like , OrNVorf61-like , OrNVorf41-like-1, and OrNVorf41-like-2 as genes that are required for normal VLP formation. Knockdown of OrNVorf47-like family members did not affect VLP formation but did disable binding of VLPs to V. canescens eggs and protection against encapsulation. Disabled formation of VLPs in response to RNAi knockdown of OrNVorf18-like , OrNVorf61-like , OrNVorf41-like-1, and OrNVorf41-like-2 also resulted in wasp eggs being encapsulated. In contrast, knockdown of OrNVorf76-like had no effect on VLP assembly, egg binding, or encapsulation. Altogether, reported results significantly advance our understanding of V. canescens VLP (VcVLP) formation and function. IMPORTANCE Understanding how V. canescens coopted an alphanudivirus to produce VcVLPs is of interest to the study of virus evolution. Our results show that three nudivirus core genes have essential functions in VcVLP formation, while one is essential for the novel function of binding to wasp eggs and protection from encapsulation, which is the most important immune defense of insects against parasitoids.

    ano.nymous@ccsd.cnrs.fr.invalid (Meng Mao) 23 Jan 2026

    https://hal.science/hal-05473549v1
  • [hal-05495582] Identification of differential metabolic properties potentially involved in the expansion of Enterobacteriaceae in the dysbiotic gut of patients suffering from Crohn’s Disease or Rheumatoid Arthritis.

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    ano.nymous@ccsd.cnrs.fr.invalid (Maria Ines Moreira de Gouveia) 05 Feb 2026

    https://hal.inrae.fr/hal-05495582v1
  • [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

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article

09 avril 2026

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

« RAVAGÉS »

« Une conférence théâtralisée pour sauver ta culture »
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2 sujets de thèse à pourvoir

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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
12 01

12 janvier 2026

UMR DGIMI, Université de Montpellier, campus sciences

Un poste de technicien.ne est ouvert dans notre unité !

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Il/Elle assurera le maintien d'élevages d'insectes au sein de l'insectarium DGIMI, contribuera aux collectes d’insectes et de nématodes sur le terrain ainsi qu’à leur maintien temporaire au laboratoire, et il/elle sera amené.e à participer à des expérimentations sur insectes, selon les besoins des projets de recherche en cours.

Sigle INRAe

On recrute un.e chercheur.se

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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.