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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-05213997] Lepidopteran Genomes Have Denser Transposable Elements in Smaller Chromosomes, Likely Driven by Non-allelic Homologous Recombination

    Transposable elements (TEs) drive major genome size and structural variations, yet evolutionary forces affecting their accumulation and removal remain unclear. Classical models predict that higher recombination rates lead to more efficient purifying selection, such as TE removal. However, in the painted lady butterfly (Vanessa cardui), smaller chromosomes harbor denser TE content than larger ones despite higher recombination rates. This unexpected pattern raises questions about whether similar trends occur across other Lepidoptera species and what evolutionary forces are behind this pattern. Across ten species spanning ten lepidopteran families, we investigated the relationship between chromosome size and TE organization using comparative genomics. We observed that smaller chromosomes consistently have higher TE densities in all the investigated species. Chromosome size had positive correlations with average inter-TE distance for both young (<5% divergence) and old TEs (5% to 10% divergence). However, the ratio of these distances (young/old TEs) was negatively correlated with chromosome size in eight of ten species, with two showing no statistically significant correlation, suggesting that smaller chromosomes have higher removal rates of sequence between TEs, potentially due to nonallelic homologous recombination, causing the loss of unique sequences between nonallelic homologs. Population genomics analyses showed inconsistent correlations between chromosome size and genetic diversity or selection coefficients between Danaus plexippus and Spodoptera frugiperda, ruling out the efficiency of purifying selection or selective constraint as the main driver. Taken together, we demonstrate that Lepidoptera has a unique genomic feature of denser TEs in smaller chromosomes, with nonallelic homologous recombination as a potential driving force.

    ano.nymous@ccsd.cnrs.fr.invalid (Hyerin An) 19 Aug 2025

    https://hal.inrae.fr/hal-05213997v1
  • [hal-05200120] Convergence in Symbiont‐Induced Plant‐Mediated Responses to Herbivory: Cascading Effects for Foraging Parasitoids

    Convergent evolution arises when unrelated species develop similar traits without a shared ancestral origin possessing those characteristics. While typically observed at the organismal level, it can also occur at higher levels of biological organisation. Polydnaviruses represent a striking example of convergent evolution. These viruses, divided into bracoviruses and ichnoviruses, were independently acquired by braconid and ichneumonid parasitoid wasps respectively, to deliver pathogenic genes to caterpillar hosts. Here we show convergent patterns across trophic levels, demonstrating that both bracoviruses and ichnoviruses induce changes in plant‐phenotypic traits that specifically benefit their parasitoid partners, facilitating plant‐mediated host discrimination. This is achieved through an interaction network triggered by changes in the polydnavirus‐infected herbivore (via alteration in regurgitant composition) which eventually affected parasitoids' foraging decisions. Our findings unveil a novel ecological benefit that polydnaviruses offer to their parasitoid partners through intricate, plant‐mediated effects, providing evidence of convergence in symbiont‐induced responses in terrestrial trophic systems.

    ano.nymous@ccsd.cnrs.fr.invalid (Antonino Cusumano) 05 Aug 2025

    https://hal.inrae.fr/hal-05200120v1
  • [pasteur-05212164] Summary of taxonomy changes ratified by the International Committee on Taxonomy of Viruses (ICTV) from the Animal DNA Viruses and Retroviruses Subcommittee, 2025

    The International Committee on Taxonomy of Viruses (ICTV) holds a ratification vote annually after review of newly proposed taxa by ICTV Study Groups and members of the virology community. In March 2025, the vote outcome of the 11 proposals within the mandate of the Animal DNA Viruses and Retroviruses Subcommittee was made public. Here, we provide a summary of the newly accepted proposals. These include reorganization of taxa in the realm Varidnaviria , classification of the ‘polinton-like’ viruses into a new family ( Phypoliviridae ) within a new order Archintovirales ; establishment of a new phylum ( Commensaviricota ) in the kingdom Shotokuvirae ; the establishment of a new family called Filamentoviridae with two new genera and three new species; the addition of four new genera in the family Anelloviridae with 70 new species; and the addition of 85 new species in the families Adenoviridae ( n =16), Baculoviridae ( n =5), Circoviridae ( n =5), Parvoviridae ( n =55) and Polyomaviridae ( n =4). Also, in the family Belpaoviridae , 11 species were renamed to comply with the binomial requirement for species names.

    ano.nymous@ccsd.cnrs.fr.invalid (Arvind Varsani) 17 Aug 2025

    https://pasteur.hal.science/pasteur-05212164v1

Actualités

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article

18 juillet 2025

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

Nouvelle offre de poste en mobilité interne

Un poste de technicien.ne en élevage, collectes et expérimentation appliqués aux insectes et autres invertébrés d’intérêt agronomique est ouvert en mobilité interne à INRAE. Les candidatures sont ouvertes du 16 juillet au 9 septembre.
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Nouvelle publication scientifique

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Les populations invasives au Sénégal montrent des traces d’évolution adaptative sur des gènes CYP450 pouvant expliquer leur adaptation au maïs.

photo Peter Heeling

Site web en cours de maintenance

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Des modifications de structure et de contenus s'opèrent actuellement sur le site web DGIMI

Postdoctoral Position in CRISPR/Cas9 Gene Editing in Insects (University of Montpellier)

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Location: UMR-DGIMI, University of Montpellier, France / Duration: 18 months / Start Date: Preferably from April 2025