University of Copenhagen

About: University of Copenhagen is a education organization based out in Copenhagen, Denmark. It is known for research contribution in the topics: Population & Medicine. The organization has 57645 authors who have published 149740 publications receiving 5903093 citations. The organization is also known as: Copenhagen University & Københavns Universitet.

Detection of a diverse marine fish fauna using environmental DNA from seawater samples.

Abstract: Marine ecosystems worldwide are under threat with many fish species and populations suffering from human over-exploitation This is greatly impacting global biodiversity, economy and human health Intriguingly, marine fish are largely surveyed using selective and invasive methods, which are mostly limited to commercial species, and restricted to particular areas with favourable conditions Furthermore, misidentification of species represents a major problem Here, we investigate the potential of using metabarcoding of environmental DNA (eDNA) obtained directly from seawater samples to account for marine fish biodiversity This eDNA approach has recently been used successfully in freshwater environments, but never in marine settings We isolate eDNA from ½-litre seawater samples collected in a temperate marine ecosystem in Denmark Using next-generation DNA sequencing of PCR amplicons, we obtain eDNA from 15 different fish species, including both important consumption species, as well as species rarely or never recorded by conventional monitoring We also detect eDNA from a rare vagrant species in the area; European pilchard (Sardina pilchardus) Additionally, we detect four bird species Records in national databases confirmed the occurrence of all detected species To investigate the efficiency of the eDNA approach, we compared its performance with 9 methods conventionally used in marine fish surveys Promisingly, eDNA covered the fish diversity better than or equal to any of the applied conventional methods Our study demonstrates that even small samples of seawater contain eDNA from a wide range of local fish species Finally, in order to examine the potential dispersal of eDNA in oceans, we performed an experiment addressing eDNA degradation in seawater, which shows that even small (100-bp) eDNA fragments degrades beyond detectability within days Although further studies are needed to validate the eDNA approach in varying environmental conditions, our findings provide a strong proof-of-concept with great perspectives for future monitoring of marine biodiversity and resources

Functions of Macronutrients

Abstract: Publisher Summary This chapter focuses on the role played by various macronutrients such as nitrogen (N), sulfur (S), phosphorus (P), magnesium (Mg), calcium (Ca), and potassium (K) in plant metabolism and growth and describes the symptoms of deficiency and toxicity of these macronutrients. N is the most essential element required after carbon, and it plays a central role in plant metabolism as a constituent of proteins, nucleic acids, chlorophyll, coenzymes, phytohormones, and secondary metabolites. When it is taken as ammonium or nitrate, it is assimilated into amino acids either in the roots or shoots and within the plant, it is translocated as nitrate or amino acids. Sulfur is taken up as sulphate and assimilated into S-containing amino acids such as cysteine that are used to synthesize S-containing enzymes and coenzymes as well as secondary compounds such as phytochelatins (detoxification of metals) or aliins and glucosinolates (feeding deterrents). Phosphorus is a structural element in nucleic acids, and as a component of adenosine phosphates, it plays an important role in energy transfer, and it is also essential for transfer of carbohydrates in leaf cells. Magnesium is a component of chlorophyll, and it is required for photosynthesis and protein synthesis. Calcium is important for cell wall and membrane stabilization, osmoregulation, and as second messenger, thereby allowing plants to regulate developmental processes in response to environmental stimuli. The main role of K is osmoregulation, which is important for cell extension and stomata movement, and it affects loading of sucrose and the rate of mass flow-driven solute movement within the plant.