Capítulos de libros

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Browsing Capítulos de libros by browse.metadata.categoriaods "14 Vida submarina"

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    A Vision for Global Biodiversity Monitoring With Citizen Science
    (2018) Pocock, Michael J. O.; Chandler, Mark; Bonney, Rick; Thornhill, Ian; Albin, Anna; August, Tom; Bachman, Steven; Brown, Peter M. J.; Fernandes Cunha, Davi Gasparini; Grez, Audrey; Jackson, Colin; Peters, Monica; Rabarijaon, Narindra Romer; Roy, Helen E.; Zaviezo Palacios, Tania; Danielsen, Finn
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    Biogeographic regionalization
    (2010) Moreira Muñoz, Andrés
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    Emiliania huxleyi endures N-limitation with an efficient metabolic budgeting and effective ATP synthesis
    (2014) Rokitta, Sebastian D.; Dassow, Peter von; Rost, Björn.; John, Uwe.
    Abstract Background Global change will affect patterns of nutrient upwelling in marine environments, potentially becoming even stricter regulators of phytoplankton primary productivity. To better understand phytoplankton nutrient utilization on the subcellular basis, we assessed the transcriptomic responses of the life-cycle stages of the biogeochemically important microalgae Emiliania huxleyi to nitrogen-limitation. Cells grown in batch cultures were harvested at ‘early’ and ‘full’ nitrogen-limitation and were compared with non-limited cells. We applied microarray-based transcriptome profilings, covering ~10.000 known E. huxleyi gene models, and screened for expression patterns that indicate the subcellular responses. Results The diploid life-cycle stage scavenges nitrogen from external organic sources and -like diatoms- uses the ornithine-urea cycle to rapidly turn over cellular nitrogen. The haploid stage reacts similarly, although nitrogen scavenging is less pronounced and lipid oxidation is more prominent. Generally, polyamines and proline appear to constitute major organic pools that back up cellular nitrogen. Both stages induce a malate:quinone-oxidoreductase that efficiently feeds electrons into the respiratory chain and drives ATP generation with reduced respiratory carbon throughput. Conclusions The use of the ornithine-urea cycle to budget the cellular nitrogen in situations of limitation resembles the responses observed earlier in diatoms. This suggests that underlying biochemical mechanisms are conserved among distant clades of marine phototrophic protists. The ornithine-urea cycle and proline oxidation appear to constitute a sensory-regulatory system that monitors and controls cellular nitrogen budgets under limitation. The similarity between the responses of the life-cycle stages, despite the usage of different genes, also indicates a strong functional consistency in the responses to nitrogen-limitation that appears to be owed to biochemical requirements. The malate:quinone-oxidoreductase is a genomic feature that appears to be absent from diatom genomes, and it is likely to strongly contribute to the uniquely high endurance of E. huxleyi under nutrient limitation.
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    From molecules to ecosystem functioning: insight into new approaches to taxonomy to monitor harmful algae diversity in Chile
    (2022) Mardones, J. I.; Krock, B.; Marcus, L.; Alves-de-Souza, C.; Nagai, S.; Yarimizu, K.; Clément, A.; Correa, N.; Silva, S.; Paredes, J.; Von Dassow, Peter
    Harmful algal blooms (HABs) are a major concern for Chilean scientists and governmental authorities, due to their deleterious effects on the aquaculture industry, resulting in complex sanitary, economic, and social problems. Increasingly, intense and frequent HABs events have distressed the aquaculture industry in recent years, especially for the occurrence of previously unreported toxic microalgae species. In the context of HAB monitoring programs, we review recent major advances in new approaches that have enabled deeper understanding of HAB species diversity in Chile. In particular, molecular approaches have revealed exceptional cryptic diversity, and chemotaxonomic approaches exposed the presence of new phycotoxins belonging to still undetected HAB species using conventional light microscopy. New advances in the detection of ichthyotoxins through the use of a fish cell line assay promises an early incorporation of this technique in routine monitoring of community composition. Emerging imaging flow cytometry is progressively pushing monitoring to more automated capabilities, and citizen science is gradually involving local communities in the complex phenomenon of harmful algal blooms