Oyster hemolymph is a complex and dynamic ecosystem hosting bacteria, protists and viruses
|Author(s)||Dupont Samuel1, Lokmer A.2, Corre E.3, Auguet Jean-Christophe4, Petton Bruno5, Toulza E.13, Montagnani Caroline1, Tanguy G.6, Pecqueur D.7, Salmeron C.7, Guillou L.8, Desnues C.9, 10, La Scola B.11, 12, Bou Khalil J.12, de Lorgeril Julien1, Mitta Guillaume13, Gueguen Yannick1, Escoubas Jean Michel14|
|Affiliation(s)||1 : IHPE, Univ. Montpellier, CNRS, Ifremer, Univ. Montpellier, Univ. Perpignan Via Domitia, 34095, Montpellier, France
2 : Coastal Ecology, Wadden Sea Station Sylt, Alfred Wegener Institute - Helmholtz Centre for Polar and Marine Research, List auf Sylt, German
3 : Sorbonne Université, CNRS, FR2424 ABiMS (Analysis and Bioanalysis for Marine Sciences), Station Biologique de Roscoff SBR, 29680, Roscoff, France
4 : MARBEC, Université Montpellier, CNRS, IFREMER, IRD, CC093, place Eugène Bataillon, 34095, Montpellier, France
5 : Ifremer, LEMAR UMR 6539, 11 presqu’île du Vivier, 29840, Argenton-en-Landunvez, France
6 : Sorbonne Université, CNRS, FR2424, Genomer, Station Biologique de Roscoff SBR, 29680, Roscoff, France
7 : Observatoire Océanologique de Banyuls sur Mer, FR 3724, BioPIC, CNRS/SU, Avenue Pierre Fabre, 66650, Banyuls-sur-Mer, France
8 : Sorbonne Université, CNRS, UMR7144 Adaptation et Diversité en Milieu Marin, Ecology of Marine Plankton (ECOMAP), Station Biologique de Roscoff SBR, 29680, Roscoff, France
9 : Aix-Marseille Université, IRD 257, Assistance-Publique des Hôpitaux de Marseille, UMR Microbes, Evolution, Phylogeny and Infections (MEPHI), IHU Méditerranée Infection, 13005, Marseille, France
10 : Aix-Marseille Université, Université de Toulon, CNRS, IRD, Mediterranean Institute of Oceanography, UM 110, 13288, Marseille, France
11 : Microbes, Evolution, Phylogeny and Infection (MEΦI), Aix-Marseille Université UM63, Institut de Recherche pour le Développement IRD 198, Assistance Publique – Hôpitaux de Marseille (AP-HM), Marseille, France
12 : Institut Hospitalo-Universitaire (IHU) - Méditerranée Infection, Marseille, France
13 : IHPE, Univ. Montpellier, CNRS, Ifremer, Univ. Montpellier, Univ. Perpignan Via Domitia, 34095, Montpellier, France
14 : IHPE, Univ. Montpellier, CNRS, Ifremer, Univ. Montpellier, Univ. Perpignan Via Domitia, 34095, Montpellier, France
|Source||Animal Microbiome (2524-4671) (Springer Science and Business Media LLC), 2020-12 , Vol. 2 , N. 1 , P. 12 (16p.)|
|Keyword(s)||Oyster genetic background, Hemolymph microbiota dynamics, Early-life microbiota, Trans-kingdom interactions, Crassostrea gigas, Within-host ecosystem|
The impact of the microbiota on host fitness has so far mainly been demonstrated for the bacterial microbiome. We know much less about host-associated protist and viral communities, largely due to technical issues. However, all microorganisms within a microbiome potentially interact with each other as well as with the host and the environment, therefore likely affecting the host health.
We set out to explore how environmental and host factors shape the composition and diversity of bacterial, protist and viral microbial communities in the Pacific oyster hemolymph, both in health and disease. To do so, five oyster families differing in susceptibility to the Pacific oyster mortality syndrome were reared in hatchery and transplanted into a natural environment either before or during a disease outbreak. Using metabarcoding and shotgun metagenomics, we demonstrate that hemolymph can be considered as an ecological niche hosting bacterial, protist and viral communities, each of them shaped by different factors and distinct from the corresponding communities in the surrounding seawater. Overall, we found that hemolymph microbiota is more strongly shaped by the environment than by host genetic background. Co-occurrence network analyses suggest a disruption of the microbial network after transplantation into natural environment during both non-infectious and infectious periods. Whereas we could not identify a common microbial community signature for healthy animals, OsHV-1 μVar virus dominated the hemolymph virome during the disease outbreak, without significant modifications of other microbiota components.
Our study shows that oyster hemolymph is a complex ecosystem containing diverse bacteria, protists and viruses, whose composition and dynamics are primarily determined by the environment. However, all of these are also shaped by oyster genetic backgrounds, indicating they indeed interact with the oyster host and are therefore not only of transient character. Although it seems that the three microbiome components respond independently to environmental conditions, better characterization of hemolymph-associated viruses could change this picture.