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Abstract Coral bleaching events from thermal stress are increasing globally in duration, frequency, and intensity. While bleaching can cause mortality, some corals survive, reacquire symbionts, and recover. We experimentally bleachedMontipora capitatato examine molecular and physiological differences between corals that recover (resilient) and those that die (susceptible). Corals were collected and monitored for eight months post-bleaching to identify genets with long-term resilience. Using an integrated systems-biology approach that included quantitative proteomics, 16S rRNA sequencing to characterize the coral microbiome, total coral lipids, symbiont community composition and density, we explored molecular-level mechanisms of tolerance in corals pre- and post-bleaching. Prior to thermal stress, resilient corals have a more diverse microbiome and abundant proteins essential for carbon acquisition, symbiont retention, and pathogen resistance. Protein signatures of susceptible corals showed early symbiont rejection and utilized urea for carbon and nitrogen. Our results reveal molecular factors for surviving bleaching events and identify diagnostic protein biomarkers for reef management and restoration. 

Since the discovery of perchlorates in martian soils, astrobiologists have been curious if and how life could survive in these low-water, high-salt environments. Perchlorates induce chaotropic and oxidative stress but can also confer increased cold tolerance in some extremophiles. Though bacterial survival has been demonstrated at subzero temperatures and in perchlorate solution, proteomic analysis of cells growing in an environment like martian regolith brines-perchlorate with subzero temperatures-has yet to be demonstrated. By defining biosignatures of survival and growth in perchlorate-amended media at subzero conditions, we move closer to understanding the mechanisms that underlie the feasibility of life on Mars. Colwellia psychrerythraea str. 34H (Cp34H), a marine psychrophile, was exposed to perchlorate ions in the form of a diluted Phoenix Mars Lander Wet Chemistry Laboratory solution at -1°C and -5°C. At both temperatures in perchlorate-amended media, Cp34H grew at reduced rates. Mass spectrometry-based proteomics analyses revealed that proteins responsible for mitigating effects of oxidative and chaotropic stress increased, while cellular transport proteins decreased. Cumulative protein signatures suggested modifications to cell-cell or cell-surface adhesion properties. These physical and biochemical traits could serve as putative identifiable biosignatures for life detection in martian environments. 

Diel rhythms are observed across taxa and are important for maintaining synchrony between the environment and organismal physiology. A striking example of this is the diel vertical migration undertaken by zooplankton, some of which, such as the 5 mm-long copepod Pleuromamma xiphias (P. xiphias), migrate hundreds of meters daily between the surface ocean and deeper waters. Some of the molecular pathways that underlie the expressed phenotype at different stages of this migration are entrained by environmental variables (e.g., day length and food availability), while others are regulated by internal clocks. We identified a series of proteomic biomarkers that vary across ocean DVM and applied them to copepods incubated in 24 h of darkness to assess circadian control. The dark-incubated copepods shared some proteomic similarities to the ocean-caught copepods (i.e., increased abundance of carbohydrate metabolism proteins at night). Shipboard-incubated copepods demonstrated a clearer distinction between night and day proteomic profiles, and more proteins were differentially abundant than in the in situ copepods, even in the absence of the photoperiod and other environmental cues. This pattern suggests that there is a canalization of rhythmic diel physiology in P. xiphias that reflects likely circadian clock control over diverse molecular pathways. 

In May and June of 2021, marine microbial samples were collected for DNA sequencing in East Sound, WA, USA every 4 hours for 22 days. This high temporal resolution sampling effort captured the last 3 days of aRhizosoleniasp. bloom, the initiation and complete bloom cycle ofChaetoceros socialis(8 days), and the following bacterial bloom (2 days). Metagenomes were completed on the time series, and the dataset includes 128 size-fractionated microbial samples (0.22–1.2 µm), providing gene abundances for the dominant members of bacteria, archaea, and viruses. This dataset also has time-matched nutrient analyses, flow cytometry data, and physical parameters of the environment at a single point of sampling within a coastal ecosystem that experiences regular bloom events, facilitating a range of modeling efforts that can be leveraged to understand microbial community structure and their influences on the growth, maintenance, and senescence of phytoplankton blooms. 

The recent rise of ‘omics and other molecular research technologies alongside improved techniques for tissue preservation have broadened the scope of marine mammal research. Collecting biological samples from wild marine mammals is both logistically challenging and expensive. To enhance the power of marine mammal research, great effort has been made in both the field and the laboratory to ensure the scientific integrity of samples from collection through processing, supporting the long‐term use of precious samples across a broad range of studies. However, identifying the best methods of sample preservation can be challenging, especially as this technological toolkit continues to evolve and expand. Standardizing best practices could maximize the scientific value of biological samples, foster multi‐institutional collaborative efforts across fields, and improve the quality of individual studies by removing potential sources of error from the collection, handling, and preservation processes. With these aims in mind, we summarize relevant literature, share current expert knowledge, and suggest best practices for sample collection and preservation. This manuscript is intended as a reference resource for scientists interested in exploring collaborative studies and preserving samples in a suitable manner for a broad spectrum of analyses, emphasizing support for ‘omics technologies. 

ABSTRACT Teleost fishes are a highly diverse, ecologically essential group of aquatic vertebrates that include coho salmon (Oncorhynchus kisutch). Coho are semelparous and all ovarian follicles develop synchronously. Owing to their ubiquitous distribution, teleosts provide critical sources of food worldwide through subsistence, commercial fisheries, and aquaculture. Enhancement of hatchery practices requires detailed knowledge of teleost reproductive physiology. Despite decades of research on teleost reproductive processes, an in‐depth proteome of teleost ovarian development has yet to be generated. We have described a coho salmon ovarian proteome of over 5700 proteins, generated with data independent acquisition, revealing the proteins that change through the transition from primary to secondary ovarian follicle development. This transition is critical during the onset of puberty and for determining egg quality and embryonic development. Primary follicle development was marked by differential abundances of proteins in carbohydrate metabolism, protein turnover, and the complement pathway, suggesting elevated metabolism as the follicles develop through stages of oogenesis. The greatest proteomic shift occurred during the transition from primary to secondary follicle growth, with increased abundance of proteins underlying cortical alveoli formation, extracellular matrix reorganization, iron binding, and cell–cell signaling. This work provides a foundation for identifying biomarkers of salmon oocyte stage and quality. 

Abstract The heterotrophic marine bacterium,Ruegeria pomeroyi, was experimentally cultured under environmentally realistic carbon conditions and with a tracer-level addition of¹³C-labeled leucine to track bacterial protein biosynthesis through growth phases. A combination of methods allowed observation of real-time bacterial protein production to understand metabolic priorities through the different growth phases. Over 2000 proteins were identified in each experimental culture from exponential and stationary growth phases. Within two hours of the¹³C-labeled leucine addition,R.pomeroyisignificantly assimilated the newly encountered substrate into new proteins. This dataset provides a fundamental baseline for understanding growth phase differences in molecular physiology of a cosmopolitan marine bacterium.