RNA-Seq of shallow-water mussel Mytilus galloprovincialis under in situ hydrostatic pressure exposure
Ontology highlight
ABSTRACT: Recent studies have unveiled the deep sea as a rich biosphere, populated by species descended from shallow-water ancestors post-mass extinctions. Research on genomic evolution and microbial symbiosis has shed light on how these species thrive in extreme deep-sea conditions. However, early adaptation stages, particularly the roles of conserved genes and symbiotic microbes, remain inadequately understood. This study examined transcriptomic and microbiome changes in shallow-water mussels Mytilus galloprovincialis exposed to deep-sea conditions at the Site-F cold seep in the South China Sea. Results reveal complex gene expression adjustments in stress response, immune defense, homeostasis, and energy metabolism pathways during adaptation. After 10 days of deep-sea exposure, shallow-water mussels and their microbial communities closely resembled those of native deep-sea mussels, demonstrating host and microbiome convergence in response to adaptive shifts. Notably, methanotrophic bacteria, key symbionts in native deep-sea mussels, emerged as a dominant group in the exposed mussels. Host genes involved in immune recognition and endocytosis correlated significantly with the abundance of these bacteria. Overall, our analyses provide insights into adaptive transcriptional regulation and microbiome dynamics of mussels in deep-sea environments, highlighting the roles of conserved genes and microbial community shifts in adapting to extreme environments.
Project description:Colonization of deep-sea hydrothermal vents by invertebrates was made efficient through their adaptation to a symbiotic lifestyle with chemosynthetic bacteria, the primary producers of these ecosystems. Anatomical adaptations such as the establishment of specialized cells or organs have been evidenced in numerous deep-sea invertebrates. However, very few studies detailed global inter-dependencies between host and symbionts in these ecosystems. In this study, we proposed to describe, using a proteo-transcriptomic approach, the effects of symbionts on the deep-sea mussel Bathymodiolus azoricus’ molecular biology. We induced an in situ depletion of symbionts and compared the proteo-transcriptome of the gills of mussels in three conditions: symbiotic mussels (natural population), symbiont-depleted mussels and aposymbiotic mussels
Project description:Microbially influenced corrosion (MIC) poses a major threat to metal structures across various industries, resulting in substantial economic losses and environmental risks. As deep-sea exploration expands, understanding MIC under high hydrostatic pressure becomes increasingly critical. Microorganisms in these extreme environments undergo distinct structural and metabolic adaptations to survive and thrive. In this study, we employed a proteomic approach to examine the lifestyle and corrosive potential of two sulfate-reducing bacteria (SRB) species with different pressure optima under simulated depths ranging from the sea surface to 3000 meters. Species-specific corrosion mechanisms and unique proteomic signatures associated with pressure adaptation were identified, correlating with opposing trends in corrosion rates. Our findings emphasize the need to characterize microbial physiology in relation to environmental conditions to better predict corrosion risks in extreme deep-sea settings.
Project description:We designed an experimental setup to investigate the transcriptomic and proteomic responses of the hyperthermophilic archaeon Pyrococcus furiosus to heat and cold shock. P. furiosus is a model organism for studying microbial adaptation to extreme environments, including deep-sea hydrothermal vents with temperature gradients ranging from 1°C to 400°C. We aimed to simulate critical conditions where P. furiosus cannot grow and to examine the immediate response to thermal stress as well as the recovery process.
Project description:Marine microorganisms inhabiting the bathypelagic zone (1000 m - 4000 m) are pivotal to biogeochemical cycling. However, a comprehensive understanding of microbial community structure and their metabolic activities adaptations to the extreme deep-sea conditions remains elusive. In this study, we employed a metaproteomic approach to investigate the protein profiles of microbial communities spanning the surface and bathypelagic layers of the South China Sea (SCS) and performed a comparative analysis with metagenomic data. The metaproteome and metagenome showed low correlation in functional expression but a high correlation at the phylum level. High-abundance genes were more likely to be translated into proteins, with protein over-representation observed in energy conversion and matter transport processes. Short-chain amide porins facilitate substance exchange and maintain cellular homeostasis, enabling Methylococcales to adapt to deep-sea conditions and actively oxidize methane. Flexible energy utilization strategies, such as CO oxidation, enable Propionibacteriales to thrive in deep-sea environments. This study highlights the significance of microbial enzyme resources and offers valuable insights into the adaptations of deep-sea microorganisms, emphasizing their considerable application potential.
2024-12-02 | PXD058504 |
Project description:First mitochondrial genomes of Chrysopetalidae (Annelida) from shallow-water and deep-sea chemosynthetic environments
Project description:The Lucinidae is a large family of marine bivalves. They occur in diverse habitats from shallow-water seagrass sediments to deep-sea hydrothermal vents. All members of this family so far investigated host intracellular sulfur-oxidizing symbionts that belong to the Gammaproteobacteria. We recently discovered the capability for nitrogen fixation in draft genomes of the symbionts of Loripes lucinalis from the Bay of Fetovaia, Elba, Italy. With proteomics, we investigated whether the genes for nitrogen fixation are expressed by the symbionts.
2016-08-19 | PXD004536 | Pride
Project description:Microbial diversity in deep sea artificial environments
Project description:Bathymodiolin mussels are a group of bivalves associated with deep-sea reducing habitats, such as hydrothermal vents and cold seeps. These mussels usually engage in an obligatory symbiosis with sulfur and/or methane oxidizing Gammaproteobacteria. In addition to these bacteria, Bathymodiolus heckerae that inhabit gas and oil seeps in Campeche Bay, the southern Gulf of Mexico, host bacteria phylogenetically with the Cycloclasticus genus. We recently discovered the capability for short-chain alkane degradation in draft genomes of symbiotic Cycloclasticus. With proteomics, we investigated whether the genes required for this process are expressed by the symbionts.
Project description:Aqueous-soluble hydrocarbons dissolve into the ocean’s interior and structure deep-sea microbial populations influenced by natural oil seeps and spills. n-Pentane is a seawater-soluble, volatile compound abundant in petroleum products and reservoirs and will partition to the deep-water column following release from the seafloor. In this study, we explore the ecology and niche partitioning of two free-living Cycloclasticus strains recovered from seawater incubations with n-pentane and distinguish them as an open ocean variant and a seep-proximal variant, each with distinct capabilities for hydrocarbon catabolism.
Project description:“Bathymodiolus” childressi is a species of deep-sea mussels found predominantly in the Gulf of Mexico harbouring a methane oxidizing symbiont (MOX). Ca. Endonucleobacter is a gammaproteobacterial intranuclear parasite that infects the ciliated edge cells of the deep-sea mussel “B.” childressi. After a single Ca. Endonucleobacter cell invades the host nucleus, it proliferates massively, increasing the volume of the nucleus up to 50 fold. It is hypothesized that intranuclear parasites use host chromatin as a nutritional source, however, this would lead to a destabilization of the replication niche. The aim of this study was to investigate how Ca. Endonucleobacter thrives in the nucleus and how it affects the host cell using various “-omics' ' approaches. In addition to protein identification we generated a high quality genome draft for Ca. Endonucleobacter using a hybrid assembly pipeline (PacBio + Illumina reads). We annotated this high quality genome draft and used it as a reference to identify the proteins responsible for the molecular interaction between Ca. Endonucleobacter and its host cell. The 12 specimens of “B.” childressi analyzed in this study were collected during five dives from the Mississippi Canyon site (MC853, 28º07’ N; -089º08’ W) and the Green Canyon site (GC234, 27º45’ N; -091º13’ W) at a water depth of 1,070 and 540 m, respectively. The mussels were selected according to their degree of Ca. Endonucleobacter infection. According to this criterion, the “B.” childressi specimens were divided into two conditions: 8 were classified as “infected”, while 4 were classified as “non-infected” (negative control). For each specimen, we prepare microdissected ciliated edge samples in triplicates.