Insight into OsHV-1 persistence phase in Pacific oyster spat
Abstract
The ostreid herpesvirus type 1 (OsHV-1) is a major pathogen of the Pacific oyster (Magallana gigas), causing recurrent episodes of spat mortality worldwide. While OsHV-1 replication and associated outbreaks occur at moderate seawater temperatures (16-22 °C), the virus becomes largely undetectable during colder months, raising the question of how it persists between epidemic episodes. In this study, we investigated the potential of Pacific oyster spat to act as reservoirs of OsHV-1. Our approach combined two-year field monitoring in a major French production area (Marennes-Oléron Bay, France) with controlled cohabitation assays, molecular detection by qPCR and ultra-deep DNA/RNA sequencing. Our results show that OsHV-1 can persist in asymptomatic spat at seawater temperatures below 13 °C, and can reactivate into a lytic phase once temperatures rise and remain above 16 °C. Sequencing analyses confirmed the presence of viral genomic fragments, but revealed extremely limited transcriptional activity. These findings support the hypothesis that OsHV-1 establishes a latent state in Pacific oyster spat, with a non-integrated viral genome during the persistent phase, and that early cohorts play a particularly important role in this process. They also emphasise the necessity of targeted molecular approaches to fully elucidate the mechanisms underlying herpesvirus persistence in marine invertebrates.
Related
- Extracellular redox regulation in Pacific oyster mucosal immunity and microbiota homeostasis
- Longitudinal persistence of EEG brain fingerprints:phase and complex coherency geometry across sessions andfunctional states
- Variation in hypoxia tolerance is driven by evolutionary changes in gene regulation in the eastern oyster
- Parallel differentiation extends beyond chromosomal inversions to small genomic islands on a background of rampant gene flow in the European flat oyster (Ostrea edulis)
- Chromosome-level genome assembly of the Olympia oyster (Ostrea lurida), the only oyster species native to the West Coast of North America
BibTeX
@article{dottomaurel2026insight,
title = {{Insight into OsHV-1 persistence phase in Pacific oyster spat}},
author = {Aurelie Dotto-Maurel and Isabelle Arzul and Adrien Touzet and Pierrick Barbier and Germain Chevignon and Benjamin Morga},
journal = {Aquaculture Reports},
year = {2026},
month = nov,
doi = {10.1016/j.aqrep.2026.103804},
url = {https://hal.science/hal-05854095v1},
note = {CC BY},
}
RIS
TY - JOUR
TI - Insight into OsHV-1 persistence phase in Pacific oyster spat
AU - Aurelie Dotto-Maurel
AU - Isabelle Arzul
AU - Adrien Touzet
AU - Pierrick Barbier
AU - Germain Chevignon
AU - Benjamin Morga
PY - 2026
DA - 2026/11/05
JO - Aquaculture Reports
DO - 10.1016/j.aqrep.2026.103804
UR - https://hal.science/hal-05854095v1
AB - The ostreid herpesvirus type 1 (OsHV-1) is a major pathogen of the Pacific oyster (Magallana gigas), causing recurrent episodes of spat mortality worldwide. While OsHV-1 replication and associated outbreaks occur at moderate seawater temperatures (16-22 °C), the virus becomes largely undetectable during colder months, raising the question of how it persists between epidemic episodes. In this study, we investigated the potential of Pacific oyster spat to act as reservoirs of OsHV-1. Our approach combined two-year field monitoring in a major French production area (Marennes-Oléron Bay, France) with controlled cohabitation assays, molecular detection by qPCR and ultra-deep DNA/RNA sequencing. Our results show that OsHV-1 can persist in asymptomatic spat at seawater temperatures below 13 °C, and can reactivate into a lytic phase once temperatures rise and remain above 16 °C. Sequencing analyses confirmed the presence of viral genomic fragments, but revealed extremely limited transcriptional activity. These findings support the hypothesis that OsHV-1 establishes a latent state in Pacific oyster spat, with a non-integrated viral genome during the persistent phase, and that early cohorts play a particularly important role in this process. They also emphasise the necessity of targeted molecular approaches to fully elucidate the mechanisms underlying herpesvirus persistence in marine invertebrates.
SN - 2352-5134
SN - 2352-5134
ER -