Data from the MOSAiC Arctic Ocean drift experiment.

The Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) is a multinational interdisciplinary endeavor of a large earth system sciences community.

Ocean acidification increases domoic acid contents during a spring to summer succession of coastal phytoplankton.

Enrichment of the oceans with CO may be beneficial for some marine phytoplankton, including harmful algae. Numerous laboratory experiments provided valuable insights into the effects of elevated pCO on the growth and physiology of harmful algal species, including the production of phycotoxins. Experiments close to natural conditions are the next step to improve predictions, as they consider the complex interplay between biotic and abiotic factors that can confound the direct effects of ocean acidification.

Deciphering Patterns of Adaptation and Acclimation in the Transcriptome of Phaeocystis antarctica to Changing Iron Conditions.

The haptophyte Phaeocystis antarctica is endemic to the Southern Ocean, where iron supply is sporadic and its availability limits primary production. In iron fertilization experiments, P. antarctica showed a prompt and steady increase in cell abundance compared to heavily silicified diatoms along with enhanced colony formation.

UltraMassExplorer: a browser-based application for the evaluation of high-resolution mass spectrometric data.

Rationale: High-resolution mass spectrometry (HRMS) with high sample throughput has become an important analytical tool for the analysis of highly complex samples and data processing has become a major challenge for the user community. Evaluating direct-infusion HRMS data without automated tools for batch processing can be a time-consuming step in the analytical pipeline. Therefore, we developed a new browser-based software tool for processing HRMS data.

Impact of sequence processing and taxonomic classification approaches on eukaryotic community structure from environmental samples with emphasis on diatoms.

Next-generation sequencing is a common method for analysing microbial community diversity and composition. Configuring an appropriate sequence processing strategy within the variety of tools and methods is a nontrivial task and can considerably influence the resulting community characteristics. We analysed the V4 region of 18S rRNA gene sequences of marine samples by 454-pyrosequencing.

Bacterial communities and chemical parameters in soils and coastal sediments in response to diesel spills at Carlini Station, Antarctica.

A diesel spill occurring at Carlini Station (King George Island (Isla 25 de Mayo), South Shetland Islands) in 2009 started the study of the fate of the hydrocarbons and their effect on the bacterial communities of the Potter Cove ecosystem. Soils and sediments were sampled across the 200-meter long diesel plume towards Potter Cove four and 15months after the spill. The sampling revealed a second fuel leakage from an underground pipeline at the spill site.

Evolutionary genomics of the cold-adapted diatom Fragilariopsis cylindrus.

The Southern Ocean houses a diverse and productive community of organisms. Unicellular eukaryotic diatoms are the main primary producers in this environment, where photosynthesis is limited by low concentrations of dissolved iron and large seasonal fluctuations in light, temperature and the extent of sea ice. How diatoms have adapted to this extreme environment is largely unknown.

Effects of ocean acidification increase embryonic sensitivity to thermal extremes in Atlantic cod, Gadus morhua.

Thermal tolerance windows serve as a powerful tool for estimating the vulnerability of marine species and their life stages to increasing temperature means and extremes. However, it remains uncertain to which extent additional drivers, such as ocean acidification, modify organismal responses to temperature. This study investigated the effects of CO -driven ocean acidification on embryonic thermal sensitivity and performance in Atlantic cod, Gadus morhua, from the Kattegat.

Do drivers of biodiversity change differ in importance across marine and terrestrial systems - Or is it just different research communities' perspectives?

Cross-system studies on the response of different ecosystems to global change will support our understanding of ecological changes. Synoptic views on the planet's two main realms, the marine and terrestrial, however, are rare, owing to the development of rather disparate research communities. We combined questionnaires and a literature review to investigate how the importance of anthropogenic drivers of biodiversity change differs among marine and terrestrial systems and whether differences perceived by marine vs.

Temperature and light interactively modulate gene expression in Saccharina latissima (Phaeophyceae).

Macroalgae of the order Laminariales (kelp) are important components of cold-temperate coastal ecosystems. Major factors influencing their distribution are light (including UV radiation) and temperature. Therefore, future global environmental changes potentially will impact their zonation, distribution patterns, and primary productivity.

A first insight into the spleen transcriptome of the notothenioid fish Lepidonotothen nudifrons: Resource description and functional overview.

In this study, we describe a de novo sequencing and assembly of the spleen transcriptome of Lepidonotothen nudifrons, a notothenioid fish widely distributed around the Antarctic Peninsula and the Scotia Arc. Sequences were generated on an Illumina MiSeq system and assembled to a total of 112,477 transcripts. Putative functional annotation was possible for more than 34% of the transcripts.

In situ expression of eukaryotic ice-binding proteins in microbial communities of Arctic and Antarctic sea ice.

Ice-binding proteins (IBPs) have been isolated from various sea-ice organisms. Their characterisation points to a crucial role in protecting the organisms in sub-zero environments. However, their in situ abundance and diversity in natural sea-ice microbial communities is largely unknown.

Gene expression profiling in gills of the great spider crab Hyas araneus in response to ocean acidification and warming.

Background: Hypercapnia and elevated temperatures resulting from climate change may have adverse consequences for many marine organisms. While diverse physiological and ecological effects have been identified, changes in those molecular mechanisms, which shape the physiological phenotype of a species and limit its capacity to compensate, remain poorly understood. Here, we use global gene expression profiling through RNA-Sequencing to study the transcriptional responses to ocean acidification and warming in gills of the boreal spider crab Hyas araneus exposed medium-term (10 weeks) to intermediate (1,120 μatm) and high (1,960 μatm) PCO2 at different temperatures (5°C and 10°C).

Climate sensitivity across marine domains of life: limits to evolutionary adaptation shape species interactions.

Organisms in all domains, Archaea, Bacteria, and Eukarya will respond to climate change with differential vulnerabilities resulting in shifts in species distribution, coexistence, and interactions. The identification of unifying principles of organism functioning across all domains would facilitate a cause and effect understanding of such changes and their implications for ecosystem shifts. For example, the functional specialization of all organisms in limited temperature ranges leads us to ask for unifying functional reasons.

Genome variations associated with viral susceptibility and calcification in Emiliania huxleyi.

Emiliania huxleyi, a key player in the global carbon cycle is one of the best studied coccolithophores with respect to biogeochemical cycles, climatology, and host-virus interactions. Strains of E. huxleyi show phenotypic plasticity regarding growth behaviour, light-response, calcification, acidification, and virus susceptibility.

Characterization and analysis of a transcriptome from the boreal spider crab Hyas araneus.

Research investigating the genetic basis of physiological responses has significantly broadened our understanding of the mechanisms underlying organismic response to environmental change. However, genomic data are currently available for few taxa only, thus excluding physiological model species from this approach. In this study we report the transcriptome of the model organism Hyas araneus from Spitsbergen (Arctic).

Pan genome of the phytoplankton Emiliania underpins its global distribution.

Coccolithophores have influenced the global climate for over 200 million years. These marine phytoplankton can account for 20 per cent of total carbon fixation in some systems. They form blooms that can occupy hundreds of thousands of square kilometres and are distinguished by their elegantly sculpted calcium carbonate exoskeletons (coccoliths), rendering them visible from space.

Evolutionary force in confamiliar marine vertebrates of different temperature realms: adaptive trends in zoarcid fish transcriptomes.

Background: Studies of temperature-induced adaptation on the basis of genomic sequence data were mainly done in extremophiles. Although the general hypothesis of an increased molecular flexibility in the cold is widely accepted, the results of thermal adaptation are still difficult to detect at proteomic down to the genomic sequence level. Approaches towards a more detailed picture emerge with the advent of new sequencing technologies.

Transcriptomic analysis of acclimation to temperature and light stress in Saccharina latissima (Phaeophyceae).

Kelps, brown algae of the order Laminariales, dominate rocky shores and form huge kelp beds which provide habitat and nurseries for various marine organisms. Whereas the basic physiological and ecophysiological characteristics of kelps are well studied, the molecular processes underlying acclimation to different light and temperature conditions are still poorly understood. Therefore we investigated the molecular mechanisms underlying the physiological acclimation to light and temperature stress.

Thermal acclimation in Antarctic fish: transcriptomic profiling of metabolic pathways.

It is widely accepted that adaptation to the extreme cold has evolved at the expense of high thermal sensitivity. However, recent studies have demonstrated significant capacities for warm acclimation in Antarctic fishes. Here, we report on hepatic metabolic reorganization and its putative molecular background in the Antarctic eelpout (Pachycara brachycephalum) during warm acclimation to 5°C over 6 wk.

Average genome size: a potential source of bias in comparative metagenomics.

In gene-centric comparative metagenomics, differences in observed relative gene abundances among samples are often assumed to reflect the biological importance of individual genes in different habitats. Statistical tests and data mining for genes that represent habitat-specific adaptations are frequently based on this measure. We demonstrate that this measure is biased by the average genome size of the communities sampled.

STAMP: Extensions to the STADEN sequence analysis package for high throughput interactive microsatellite marker design.

Background: Microsatellites (MSs) are DNA markers with high analytical power, which are widely used in population genetics, genetic mapping, and forensic studies. Currently available software solutions for high-throughput MS design (i) have shortcomings in detecting and distinguishing imperfect and perfect MSs, (ii) lack often necessary interactive design steps, and (iii) do not allow for the development of primers for multiplex amplifications. We present a set of new tools implemented as extensions to the STADEN package, which provides the backbone functionality for flexible sequence analysis workflows.

Efficient evaluation of sampling quality of molecular dynamics simulations by clustering of dihedral torsion angles and Sammon mapping.

A direct conformational clustering and mapping approach for peptide conformations based on backbone dihedral angles has been developed and applied to compare conformational sampling of Met-enkephalin using two molecular dynamics (MD) methods. Efficient clustering in dihedrals has been achieved by evaluating all combinations resulting from independent clustering of each dihedral angle distribution, thus resolving all conformational substates. In contrast, Cartesian clustering was unable to accurately distinguish between all substates.

Feasibility of assessing the community composition of prasinophytes at the Helgoland Roads sampling site with a DNA microarray.

The microalgal class Prasinophyceae (Chlorophyta) contains several picoeukaryotic species, which are known to be common in temperate and cold waters and have been observed to constitute major fractions of marine picoplankton. However, reliable detection and classification of prasinophytes are mainly hampered by their small size and few morphological markers. Consequently, very little is known about the abundance and ecology of the members of this class.