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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-05410672] Transgenerational effects of a high temperature impair the resistance of the pest Spodoptera frugiperda to a parasitoid

    Insect parasitoids provide a useful ecosystem service to control pest insects. However, climate change could challenge this pest management, as insects are known to be sensitive to temperature. Furthermore, transgenerational effects, which are common in insects, could influence these effects of temperature on host-parasitoid systems. The present study therefore aimed to test the combined effects of developmental and host parental temperatures on a host-parasitoid system, using the fall armyworm (FAW) and the parasitoid Hyposoter didymator. We focused on mean temperatures of 25 and 29 °C, with a daily fluctuation of ±5 °C. The increase in mean temperatures had a significant effect on all the host parameters tested (survival, developmental rate, sex ratio, body mass) and on parasitoid success. Parasitoid success decreased between the developmental temperatures of 25 and 29 °C, and most effects of the increase in developmental temperature on FAW traits were detrimental to the parasitoid. Remarkably, we found transgenerational effects of temperature on the host resistance to parasitoids (the proportion of FAW escaping parasitism), as well as on host traits associated with the probability of parasitoids finding a host (effects on survival and developmental rates) and host quality (body mass, sex ratio). The parental temperature of 29 °C had a detrimental effect on the FAW resistance to parasitoids, but it reinforced the effects of developmental temperature on host traits that have a negative impact on parasitoids. The study shows the high thermal sensitivity of a host-parasitoid system and highlights that thermal transgenerational plasticity should be considered in host-parasitoid interactions.

    ano.nymous@ccsd.cnrs.fr.invalid (Shannon Alary) 11 Dec 2025

    https://hal.inrae.fr/hal-05410672v1
  • [hal-05438464] Unveiling the Impact of Porphyromonas gingivalis ‐Associated Periodontitis on Stroke Outcome in Mice

    Background Periodontitis is a chronic inflammatory condition with infectious origin that affects the tissues supporting the teeth. Increasing epidemiological evidence suggests that periodontitis is a risk factor for ischemic stroke with associated adverse outcomes. However, the underlying mechanism of this association remains incompletely elucidated. Methods We used a C57BL/6J mice model of ischemic stroke induced by transitory occlusion of the middle cerebral artery in the presence or absence of ligature‐induced periodontitis using Porphyromonas gingivalis ‐soaked ligatures. Stroke severity was evaluated through infarct volume, sensorimotor deficit, blood–brain barrier (BBB) integrity, and markers of systemic and brain inflammation. The direct effect of P gingivalis on BBB endothelial cells was further explored in vitro. Results Mice with P gingivalis ‐associated periodontitis showed a significant exacerbation of stroke severity: larger infarct volume, more severe sensorimotor deficit, greater BBB disruption, and increased brain neutrophil infiltration compared with sham. Systemic inflammation was also markedly elevated. Intravenous administration of P gingivalis alone, without gingival injury, before transitory occlusion of the middle cerebral artery was sufficient to amplify brain inflammation and stroke lesions. In vitro P gingivalis, through its gingipain proteases, directly impaired BBB integrity by increasing endothelial permeability and disrupting tight‐junction proteins. Conclusions Our findings demonstrate that P gingivalis ‐associated periodontitis worsens ischemic stroke outcome both indirectly by enhancing systemic and brain inflammation and directly via BBB disruption. These results highlight periodontitis as a modifiable risk factor and potential therapeutic target for improving stroke prognosis.

    ano.nymous@ccsd.cnrs.fr.invalid (Devy Diallo) 02 Jan 2026

    https://u-paris.hal.science/hal-05438464v1
  • [hal-05374380] A characterization of piARNs, their biogenesis and their targets in Spodoptera frugiperda (Lepidoptera, Noctuidae)

    Abstract PIWI-interacting RNAs (piRNAs) and PIWI proteins were initially described as involved in gametogenesis and preservation of genome integrity through the control of transposable elements (TE). 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, reproductive isolation. Spodoptera frugiperda is a major invasive insect pest species consisting of two strains with different host-plant ranges. In this paper, we characterized proteins and genomic regions involved in their biogenesis as well as TE and gene transcripts regulated by piRNAs. 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 gonads then 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 strains of Spodoptera frugiperda . Identification of TE targeted by piRNAs revealed that active transposons differ between the two strains of S. frugiperda despite of a similar TE content, as 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 in Spodoptera frugiperda . Our analysis supports that piRNAs have additional roles than silencing of transposable elements and contributes to functional annotation of the two strains genomes of Spodoptera frugiperda .

    ano.nymous@ccsd.cnrs.fr.invalid (Imène Seninet) 20 Nov 2025

    https://hal.inrae.fr/hal-05374380v1

Actualités

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article

15 janvier 2026

Rédaction : A-N. Volkoff, N. Nègre, I. Seninet

On recrute à DGIMI en 2026

Meilleurs vœux pour cette nouvelle année 2026 ! Afin de vous accompagner dans votre épanouissement professionnel, le laboratoire DGIMI vous propose des offres de recrutement au niveau technicien, assistant-ingénieur, enseignant-chercheur et chercheur :
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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.

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12 01

12 janvier 2026

Université de Montpellier, campus sciences

Poste de MCF nématodes

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Un poste de Maître de Conférences sera à pourvoir en 2026 à l'Université de Montpellier.

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12 01

12 janvier 2026

UMR DGIMI, Université de Montpellier, campus sciences

Un poste de technicien.ne devrait bientôt s’ouvrir 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.