Host-symbiont proteomes of Bathymodiolus thermophilus

ABSTRACT: Bathymodiolus mussels inhabiting deep-sea hydrothermal vents harbor bacterial symbionts in their gills, which support the animals’ diet. While the basic mechanisms of energy generation and CO2 fixation that drive these symbioses are largely established, details of molecular interactions between the symbiotic partners and adaptations to their respective habitats remain unknown. In this study, we therefore comparatively examined the genomes and proteomes of two Bathymodiolus hosts and their respective symbionts from different geographical locations. Two mussel species were proteomically compared: i) B. thermophilus mussel containing sulfur-oxidizing symbiont from the east pacific rise. thermophilus and ii) B. azoricus containing thiotrophic and methanotrophic symbionts from the mid-atlantic ridge. Symbionts (for both species) and host components (for B. azoricus) were selectively enriched using a multi-step centrifugation procedure. Enriched host and symbiont fractions along with unenriched gill foot tissue were subject to in-depth semi-quantitative proteomic analyses using the orbitrap and velos mass spectrometers. Proteins were quantified based on their spectral counts using the normalized spectral abundance factor (NSAF) method. We identified common strategies of metabolic interactions that provide mutual nutritional support between host and symbionts, such as the detoxification of ambient sulfide by the Bathymodiolus host, which provides a stable thiosulfate reservoir for the thiotrophic symbionts, and a putative amino acid cycling mechanism that could supply the host with symbiont-derived amino acids. A suite of genes and proteins putatively related to virulence or defense functions was particularly abundant in the B. thermophilus symbiont, compared to its symbiont relatives, and may pose a host species-specific adaptation. Our results reveal both, a high degree of integration between the symbiotic partners, and great potential to adapt to the prevailing environment, which facilitate the holobiont’s survival in its hydrothermal vent habitat.

OTHER RELATED OMICS DATASETS IN: PRJEB8263 PRJEB7941 PRJEB7943 PRJEB8264 PRJEB13047

INSTRUMENT(S): LTQ Orbitrap, LTQ Orbitrap Velos

ORGANISM(S): Bathymodiolus Azoricus (mussel) Bathymodiolus Thermophilus

TISSUE(S): Gill

SUBMITTER: Ruby Ponnudurai  

LAB HEAD: Thomas Schweder, Stephanie Markert

PROVIDER: PXD011639 | Pride | 2019-11-08

REPOSITORIES: Pride