Browsing by Author "Benabed, Slimania"

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    Both candidate gene and neutral genetic diversity correlate with parasite resistance in female Mediterranean mouflon
    (2019-03-05) Portanier, Elodie; Garel, Mathieu; Devillard, Sébastien; Maillard, Daniel; Poissant, Jocelyn; Galan, Maxime; Benabed, Slimania; Poirel, Marie-Thérèse; Duhayer, Jeanne; Itty, Christian; Bourgoin, Gilles
    Abstract Background Parasite infections can have substantial impacts on population dynamics and are accordingly a key challenge for wild population management. Here we studied genetic mechanisms driving parasite resistance in a large herbivore through a comprehensive approach combining measurements of neutral (16 microsatellites) and adaptive (MHC DRB1 exon 2) genetic diversity and two types of gastrointestinal parasites (nematodes and coccidia). Results While accounting for other extrinsic and intrinsic predictors known to impact parasite load, we show that both neutral genetic diversity and DRB1 are associated with resistance to gastrointestinal nematodes. Intermediate levels of multi-locus heterozygosity maximized nematodes resistance, suggesting that both in- and outbreeding depression might occur in the population. DRB1 heterozygosity and specific alleles effects were detected, suggesting the occurrence of heterozygote advantage, rare-allele effects and/or fluctuating selection. On the contrary, no association was detected between genetic diversity and resistance to coccidia, indicating that different parasite classes are impacted by different genetic drivers. Conclusions This study provides important insights for large herbivores and wild sheep pathogen management, and in particular suggests that factors likely to impact genetic diversity and allelic frequencies, including global changes, are also expected to impact parasite resistance.
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    Metabarcoding in two isolated populations of wild roe deer (Capreolus capreolus) reveals variation in gastrointestinal nematode community composition between regions and among age classes
    (2021-12-04) Beaumelle, Camille; Redman, Elizabeth M.; de Rijke, Jill; Wit, Janneke; Benabed, Slimania; Debias, François; Duhayer, Jeanne; Pardonnet, Sylvia; Poirel, Marie-Thérèse; Capron, Gilles; Chabot, Stéphane; Rey, Benjamin; Yannic, Glenn; Gilleard, John S.; Bourgoin, Gilles
    Abstract Background Gastrointestinal nematodes are ubiquitous for both domestic and wild ungulates and have varying consequences for health and fitness. They exist as complex communities of multiple co-infecting species, and we have a limited understanding of how these communities vary in different hosts, regions and circumstances or of how this affects their impacts. Methods We have undertaken ITS2 rDNA nemabiome metabarcoding with next-generation sequencing on populations of nematode larvae isolated from 149 fecal samples of roe deer of different sex and age classes in the two isolated populations of Chizé and Trois Fontaines in France not co-grazing with any domestic ungulate species. Results We identified 100 amplified sequence variants (ASVs) that were assigned to 14 gastrointestinal nematode taxa overall at either genus (29%) or species (71%) level. These taxa were dominated by parasites classically found in cervids—e.g. Ostertagia leptospicularis, Spiculopteragia spp. Higher parasite species diversity was present in the Trois Fontaines population than in the Chizé population including the presence of species more typically seen in domestic livestock (Haemonchus contortus, Bunostomum sp., Cooperia punctata, Teladorsagia circumcincta). No differences in parasite species diversity or community composition were seen in the samples collected from three zones of differing habitat quality within the Chizé study area. Young roe deer hosted the highest diversity of gastrointestinal nematodes, with more pronounced effects of age apparent in Trois Fontaines. The effect of host age differed between gastrointestinal nematode species, e.g. there was little effect on O. leptospicularis but a large effect on Trichostrongylus spp. No effect of host sex was detected in either site. Conclusions The presence of some livestock parasite species in the Trois Fontaines roe deer population was unexpected given the isolation of this population away from grazing domestic livestock since decades. Overall, our results illustrate the influence of host traits and the local environment on roe deer nemabiome and demonstrate the power of the nemabiome metabarcoding approach to elucidate the composition of gastrointestinal nematode communities in wildlife. Graphical Abstract