Ocean warming and acidification adjust inter- and intra-specific variability in the functional trait expression of polar invertebrates.

Climate change is known to affect the distribution and composition of species, but concomitant alterations to functionally important aspects of behaviour and species-environment relations are poorly constrained. Here, we examine the ecosystem ramifications of changes in sediment-dwelling invertebrate bioturbation behaviour-a key process mediating nutrient cycling-associated with near-future environmental conditions (+ 1.5 °C, 550 ppm [pCO]) for species from polar regions experiencing rapid rates of climate change.

Biogeochemical consequences of a changing Arctic shelf seafloor ecosystem.

Unprecedented and dramatic transformations are occurring in the Arctic in response to climate change, but academic, public, and political discourse has disproportionately focussed on the most visible and direct aspects of change, including sea ice melt, permafrost thaw, the fate of charismatic megafauna, and the expansion of fisheries. Such narratives disregard the importance of less visible and indirect processes and, in particular, miss the substantive contribution of the shelf seafloor in regulating nutrients and sequestering carbon. Here, we summarise the biogeochemical functioning of the Arctic shelf seafloor before considering how climate change and regional adjustments to human activities may alter its biogeochemical and ecological dynamics, including ecosystem function, carbon burial, or nutrient recycling.

Reproductive traits and population dynamics of benthic invertebrates indicate episodic recruitment patterns across an Arctic polar front.

Climate-induced changes in the ocean and sea ice environment of the Arctic are beginning to generate major and rapid changes in Arctic ecosystems, but the effects of directional forcing on the persistence and distribution of species remain poorly understood. Here, we examine the reproductive traits and population dynamics of the bivalve and sea star across a north-south transect that intersects the polar front in the Barents Sea. Both species present large oocytes indicative of short pelagic or direct development that do not differ in size-frequency between 74.

Climate-driven benthic invertebrate activity and biogeochemical functioning across the Barents Sea polar front.

Arctic marine ecosystems are undergoing rapid correction in response to multiple expressions of climate change, but the consequences of altered biodiversity for the sequestration, transformation and storage of nutrients are poorly constrained. Here, we determine the bioturbation activity of sediment-dwelling invertebrate communities over two consecutive summers that contrasted in sea-ice extent along a transect intersecting the polar front. We find a clear separation in community composition at the polar front that marks a transition in the type and amount of bioturbation activity, and associated nutrient concentrations, sufficient to distinguish a southern high from a northern low.

Interrogation of highly structured RNA with multicomponent deoxyribozyme probes at ambient temperatures.

Molecular analysis of RNA through hybridization with sequence-specific probes is challenging due to the intrinsic ability of RNA molecules to form stable secondary and tertiary structures. To overcome the energy barrier toward the probe-RNA complex formation, the probes are made of artificial nucleotides, which are more expensive than their natural counterparts and may still be inefficient. Here, we propose the use of a multicomponent probe based on an RNA-cleaving deoxyribozyme for the analysis of highly structured RNA targets.

Cascade of deoxyribozymes for the colorimetric analysis of drug resistance in Mycobacterium tuberculosis.

A visual cascade detection system has been applied to the detection and analysis of drug-resistance profile of Mycobacterium tuberculosis complex (MTC), a causative agent of tuberculosis. The cascade system utilizes highly selective split RNA-cleaving deoxyribozyme (sDz) sensors. When activated by a complementary nucleic acid, sDz releases the peroxidase-like deoxyribozyme apoenzyme, which, in complex with a hemin cofactor, catalyzes the color change of the sample's solution.

Selective Determination of Isothermally Amplified Zika Virus RNA Using a Universal DNA-Hairpin Probe in Less than 1 Hour.

The recent outbreak of the Zika virus (ZIKV) in the Americas and multiple studies that linked the virus to the cases of microcephaly and neurological complications have revealed the need for cost efficient and rapid ZIKV diagnostics tests. Here, a diagnostic platform relying on a four-way junction (4WJ)-based biosensor with electrochemical readout using a Universal DNA-Hairpin (UDH) probe for the selective recognition of an isothermally amplified ZIKV RNA fragment is developed. The 4WJ structure utilizes an electrode-immobilized stem-loop (DNA-hairpin) probe and two DNA adaptor strands complementary to both the stem-loop probe and the targeted fragment of a ZIKV amplicon.

Label-Free Pathogen Detection by a Deoxyribozyme Cascade with Visual Signal Readout.

A colorimetric nucleic acid based test for label-free pathogen detection has been developed and used for the detection of the Zika virus. The test relies on nucleic acid sequence-based amplification (NASBA) of a viral RNA followed by interrogation of the amplicon by a cascade of deoxyribozymes constituting a visual split deoxyribozyme (vsDz) probe. The probe consists of a split phosphodiesterase deoxyribozyme, which forms its catalytic core upon binding to a specific amplicon fragment.

Phosphate deficiency promotes coral bleaching and is reflected by the ultrastructure of symbiotic dinoflagellates.

Enrichment of reef environments with dissolved inorganic nutrients is considered a major threat to the survival of corals living in symbiosis with dinoflagellates (Symbiodinium sp.). We argue, however, that the direct negative effects on the symbiosis are not necessarily caused by the nutrient enrichment itself but by the phosphorus starvation of the algal symbionts that can be caused by skewed nitrogen (N) to phosphorus (P) ratios.

Shifting baselines in Antarctic ecosystems; ecophysiological response to warming in Lissarca miliaris at Signy Island, Antarctica.

The Antarctic Peninsula has experienced a rapid increase in atmospheric temperature over the last 50 years. Whether or not marine organisms thriving in this cold stenothermal environment are able to cope with warming is of concern. Here, we present changes to the growth and shell characteristics of the ecologically important, small and short lived brooding bivalve Lissarca miliaris from Signy Island, Antarctica.