Post-capture immune gene expression studies in the deep-sea hydrothermal vent mussel Bathymodiolus azoricus acclimatized to atmospheric pressure

Identification and gene expression of multiple peptidoglycan recognition proteins (PGRPs) in the deep-sea mussel Bathymodiolus azoricus , involvement in symbiosis?

“…Specifically, mechanisms involved in the interaction between host and symbiont at the cellular and/or molecular level have not been explored. To date, only a few studies have examined related question through microscopic investigations or gene expression (Won et al, 2003;Kádár et al, 2005;Boutet et al, 2011;Bettencourt et al, 2014;Barros et al, 2015). As in other symbioses, B. azoricus may regulate its symbiont population through apoptosis mechanisms or immunological responses.…”

An Insightful Model to Study Innate Immunity and Stress Response in Deep‐Sea Vent Animals: Profiling the Mussel Bathymodiolus azoricus

“…These studies provided a basis for understanding the interactions between host-immune and endosymbiont gene expressions during postcapture long-term acclimatization in plain sea water and represented an ideal model for investigating B. azoricus immune genes transcriptional activity and symbiont bacteria prevalence, in view of changes in the availability of chemical-based energy sources during acclimatization at atmospheric pressure. It also pointed out the relevance of gene expression studies while addressing the swift changes affecting metabolic adaptations and food intake fluctuations, whether induced by or as a result of the gradual loss of endosymbionts and subsequent presence of symbiont bacteria in the aquarium environment, altering thus the physiological homeostasis of B. azoricus [56]. These studies demonstrated that the transcriptional activity profiles for immune and bacterial endosymbiont genes followed a time-dependent mRNA transcriptional pattern evidenced at 24 h, 1 week, and 3 weeks acclimatization.…”

“…These studies demonstrated that the transcriptional activity profiles for immune and bacterial endosymbiont genes followed a time-dependent mRNA transcriptional pattern evidenced at 24 h, 1 week, and 3 weeks acclimatization. Furthermore, after 1 week acclimatization, vent mussels were under the influence of what appears to be a concomitant host-immune and endosymbiont gene expression, possibly indicating a physiological transition point which induces higher levels of transcriptional activity [56]. Under such circumstances, survival of vent mussels will require immune gene repertoire switching involving the differential expression (DE) of recognition, signaling, transcription, and effector genes tied to environmental parameters and to the symbiotic relationships in B. azoricus.…”

“…Under such circumstances, survival of vent mussels will require immune gene repertoire switching involving the differential expression (DE) of recognition, signaling, transcription, and effector genes tied to environmental parameters and to the symbiotic relationships in B. azoricus. Metabolic adaptations and food intake changes, whether induced as a result of the gradual loss of endosymbionts and subsequent release in the aquarium environment, are likely to affect gene transcription activities and prevalence of symbionts in gill tissues [56][57][58].…”

“…While the majority of our experiments using live vent mussels were performed shortly after their retrieval from the Menez Gwen hydrothermal vent, long-term studies with vent mussels acclimatized to atmospheric pressure conditions have hardly been addressed until recently. As above-mentioned, long-term acclimatization experiments in aquarium systems have allowed us to study the expression of bacterial symbionts genes, particularly methanotrophic and thiotrophic bacteria, over time of acclimatization while their mussel host is faced with drastic physiological challenges, metabolic adaptations, and food intake changes in an effort to adapt to an aquarium environment at atmospheric pressure and without supplementation of methane and sulfur [56]. The physiological adaptation to aquarium environment is likely to be aggravated by the expelling of endosymbionts into the aquarium environment, progressively emptying the gill tissue of its autotrophic bacteria, essential for the host vent mussel nutritional sustenance.…”