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Dr. Juan Blanco
Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Instituto de Salud Carlos III, Madrid

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0 Kinetic modelling
0 Marine Toxins
0 Harmful Algae
0 LC-MS/MS analysis
0 toxic phytoplankton

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Journal article
Published: 30 June 2021 in Toxins
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Cultures of the mussel Mytilus galloprovincialis are frequently affected by accumulation of the amnesic shellfish poisoning toxin domoic acid (DA). This species is characterized by a fast uptake and release of the toxin. In this work, the main characteristics of the uptake mechanism have been studied by incubation of digestive gland thin slices in media with different composition and DA concentration. DA uptake seems to follow Michaelis–Menten kinetics, with a very high estimated KM (1722 µg DA mL−1) and a Vmax of 71.9 µg DA g−1 h−1, which is similar to those found for other amino acids in invertebrates. Replacement of NaCl from the incubation media by Cl-choline (Na+-free medium) did not significantly reduce the uptake, but replacement by sorbitol (Na+-free and Cl-depleted medium) did. A new experiment replacing all chlorides with their equivalent gluconates (Na+- and Cl-free medium) showed an important reduction in the uptake that should be attributed to the absence of chloride, pointing to a Na+-independent, Cl (or anion-) dependent transporter. In media with Na+ and Cl, neither decreasing the pH nor adding cyanide (a metabolic inhibitor) had significant effect on DA uptake, suggesting that the transport mechanism is not H+- or ATP-dependent. In a chloride depleted medium, lowering pH or adding CN increased the uptake, suggesting that other anions could, at least partially, substitute chloride.

ACS Style

Juan Blanco; Carmen Mariño; Helena Martín; Gonzalo Álvarez; Araceli Rossignoli. Characterization of the Domoic Acid Uptake Mechanism of the Mussel (Mytilus galloprovincialis) Digestive Gland. Toxins 2021, 13, 458 .

AMA Style

Juan Blanco, Carmen Mariño, Helena Martín, Gonzalo Álvarez, Araceli Rossignoli. Characterization of the Domoic Acid Uptake Mechanism of the Mussel (Mytilus galloprovincialis) Digestive Gland. Toxins. 2021; 13 (7):458.

Chicago/Turabian Style

Juan Blanco; Carmen Mariño; Helena Martín; Gonzalo Álvarez; Araceli Rossignoli. 2021. "Characterization of the Domoic Acid Uptake Mechanism of the Mussel (Mytilus galloprovincialis) Digestive Gland." Toxins 13, no. 7: 458.

Journal article
Published: 09 June 2021 in Toxins
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The Peruvian sea is one of the most productive ecosystems in the world. Phytoplankton production provides food for fish, mammals, mollusks and birds. This trophic network is affected by the presence of toxic phytoplankton species. In July 2017, samples of phytoplankton were obtained from Paracas Bay, an important zone for scallop (Argopecten purpuratus) aquaculture in Peru. Morphological analysis revealed the presence of the genus Pseudo-nitzschia, which was isolated and cultivated in laboratory conditions. Subsequently, the monoclonal cultures were observed by scanning electron microscopy (SEM), and identified as P. multistriata, based on both the morphological characteristics, and internal transcribed spacers region (ITS2) sequence phylogenetic analysis. Toxin analysis using liquid chromatography (LC) with high-resolution mass spectrometry (HRMS) revealed the presence of domoic acid (DA) with an estimated amount of 0.004 to 0.010 pg cell−1. This is the first report of DA from the coastal waters of Peru and its detection in P. multistriata indicates that it is a potential risk. Based on our results, routine monitoring of this genus should be considered in order to ensure public health.

ACS Style

Cecil Tenorio; Gonzalo Álvarez; Sonia Quijano-Scheggia; Melissa Perez-Alania; Natalia Arakaki; Michael Araya; Francisco Álvarez; Juan Blanco; Eduardo Uribe. First Report of Domoic Acid Production from Pseudo-nitzschia multistriata in Paracas Bay (Peru). Toxins 2021, 13, 408 .

AMA Style

Cecil Tenorio, Gonzalo Álvarez, Sonia Quijano-Scheggia, Melissa Perez-Alania, Natalia Arakaki, Michael Araya, Francisco Álvarez, Juan Blanco, Eduardo Uribe. First Report of Domoic Acid Production from Pseudo-nitzschia multistriata in Paracas Bay (Peru). Toxins. 2021; 13 (6):408.

Chicago/Turabian Style

Cecil Tenorio; Gonzalo Álvarez; Sonia Quijano-Scheggia; Melissa Perez-Alania; Natalia Arakaki; Michael Araya; Francisco Álvarez; Juan Blanco; Eduardo Uribe. 2021. "First Report of Domoic Acid Production from Pseudo-nitzschia multistriata in Paracas Bay (Peru)." Toxins 13, no. 6: 408.

Journal article
Published: 07 May 2021 in Toxins
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Some diatom species of the genus Pseudo-nitzschia produce the toxin domoic acid. The depuration rate of domoic acid in Pecten maximus is very low; for this reason, king scallops generally contain high levels of domoic acid in their tissues. A transcriptomic approach was used to identify the genes differentially expressed in the P. maximus digestive gland after the injection of domoic acid. The differential expression analysis found 535 differentially expressed genes (226 up-regulated and 309 down-regulated). Protein–protein interaction networks obtained with the up-regulated genes were enriched in gene ontology terms, such as vesicle-mediated transport, response to stress, signal transduction, immune system process, RNA metabolic process, and autophagy, while networks obtained with the down-regulated genes were enriched in gene ontology terms, such as response to stress, immune system process, ribosome biogenesis, signal transduction, and mRNA processing. Genes that code for cytochrome P450 enzymes, glutathione S-transferase theta-1, glutamine synthase, pyrroline-5-carboxylate reductase 2, and sodium- and chloride-dependent glycine transporter 1 were among the up-regulated genes. Therefore, a stress response at the level of gene expression, that could be caused by the domoic acid injection, was evidenced by the alteration of several biological, cellular, and molecular processes.

ACS Style

Pablo Ventoso; Antonio Pazos; Juan Blanco; M. Pérez-Parallé; Juan Triviño; José Sánchez. Transcriptional Response in the Digestive Gland of the King Scallop (Pecten maximus) After the Injection of Domoic Acid. Toxins 2021, 13, 339 .

AMA Style

Pablo Ventoso, Antonio Pazos, Juan Blanco, M. Pérez-Parallé, Juan Triviño, José Sánchez. Transcriptional Response in the Digestive Gland of the King Scallop (Pecten maximus) After the Injection of Domoic Acid. Toxins. 2021; 13 (5):339.

Chicago/Turabian Style

Pablo Ventoso; Antonio Pazos; Juan Blanco; M. Pérez-Parallé; Juan Triviño; José Sánchez. 2021. "Transcriptional Response in the Digestive Gland of the King Scallop (Pecten maximus) After the Injection of Domoic Acid." Toxins 13, no. 5: 339.

Journal article
Published: 11 March 2021 in Environmental Pollution
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Gymnodimine A has been found in mollusks obtained along the whole northern coast of Spain from April 2017 to December 2019. This is the first time that this toxin is detected in mollusks from the Atlantic coast of Europe. The prevalence of the toxin was, in general, low, being detected on average in approximately 6% of the obtained samples (122 out of 1900). The concentrations recorded were also, in general, low, with a median of 1.3 μg kg−1, and a maximum value of 23.93 μg kg−1. The maxima of prevalence and concentration were not geographically coincident, taking place the first at the easternmost part of the sampled area and the second at the westernmost part. In most cases (>94%), gymnodimine A and 13-desmethyl spirolide C were concurrently detected, suggesting that Alexandrium ostenfeldii could be the responsible producer species. The existence of cases in which gymnodimine A was detected alone suggests also that a Karenia species could also be involved. The geographical heterogeneity of the distribution suggests that blooms of the producer species are mostly local. Not all bivalves are equally affected, clams being less affected than mussels, oysters, and razor clams. Due to their relatively low toxicity, and their low prevalence and concentration, it seems that these toxins do not pose an important risk for the mollusk consumers in the area.

ACS Style

J.Pablo Lamas; Fabiola Arévalo; Ángeles Moroño; Jorge Correa; Araceli E. Rossignoli; Juan Blanco. Gymnodimine A in mollusks from the north Atlantic Coast of Spain: Prevalence, concentration, and relationship with spirolides. Environmental Pollution 2021, 279, 116919 .

AMA Style

J.Pablo Lamas, Fabiola Arévalo, Ángeles Moroño, Jorge Correa, Araceli E. Rossignoli, Juan Blanco. Gymnodimine A in mollusks from the north Atlantic Coast of Spain: Prevalence, concentration, and relationship with spirolides. Environmental Pollution. 2021; 279 ():116919.

Chicago/Turabian Style

J.Pablo Lamas; Fabiola Arévalo; Ángeles Moroño; Jorge Correa; Araceli E. Rossignoli; Juan Blanco. 2021. "Gymnodimine A in mollusks from the north Atlantic Coast of Spain: Prevalence, concentration, and relationship with spirolides." Environmental Pollution 279, no. : 116919.

Journal article
Published: 03 November 2020 in Toxins
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Domoic acid (DA), the main toxin responsible for Amnesic Shellfish Poisoning, frequently affects the marine resources of Chile and other countries across the South Pacific, thus becoming a risk for human health. One of the affected resources is the scallop Argopecten purpuratus. Even though this species has a high commercial importance in Northern Chile and Peru, the characteristics of its DA depuration are not known. In this work, the DA depuration was studied by means of two experiments: one in controlled (laboratory) and another in natural conditions. All organs of A. purpuratus depurated the toxin very quickly in both experiments. In some organs, an increase or a very small decrease of toxin was detected in the early depuration steps. Several models were used to describe this kinetics. The one that included toxin transfer between organs and independent depuration from each organ was the model that best fit the data. It seems, therefore, that the DA in this species is quickly transferred from the digestive gland to all other organs, which release it into the environment. Physiological differences in the two experiments have been shown to have some effect on the depuration from each organ but the actual reasons are still unknown.

ACS Style

Gonzalo Álvarez; José Rengel; Michael Araya; Francisco Álvarez; Roberto Pino; Eduardo Uribe; Patricio Díaz; Araceli Rossignoli; Américo López-Rivera; Juan Blanco. Rapid Domoic Acid Depuration in the Scallop Argopecten purpuratus and Its Transfer from the Digestive Gland to Other Organs. Toxins 2020, 12, 698 .

AMA Style

Gonzalo Álvarez, José Rengel, Michael Araya, Francisco Álvarez, Roberto Pino, Eduardo Uribe, Patricio Díaz, Araceli Rossignoli, Américo López-Rivera, Juan Blanco. Rapid Domoic Acid Depuration in the Scallop Argopecten purpuratus and Its Transfer from the Digestive Gland to Other Organs. Toxins. 2020; 12 (11):698.

Chicago/Turabian Style

Gonzalo Álvarez; José Rengel; Michael Araya; Francisco Álvarez; Roberto Pino; Eduardo Uribe; Patricio Díaz; Araceli Rossignoli; Américo López-Rivera; Juan Blanco. 2020. "Rapid Domoic Acid Depuration in the Scallop Argopecten purpuratus and Its Transfer from the Digestive Gland to Other Organs." Toxins 12, no. 11: 698.

Journal article
Published: 04 June 2020 in Toxins
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The king scallop Pecten maximus retains the amnesic shellfish poisoning toxin, domoic acid (DA), for a long time. Most of the toxin is accumulated in the digestive gland, but this organ contains several cell types whose contribution to the accumulation of the toxin is unknown. Determining the time-course of the depuration by analyzing whole organs is difficult because the inter-individual variability is high. A sampling method, using biopsies of the digestive gland, has been developed. This method allows for repetitive sampling of the same scallop, but the representativeness of the samples obtained in this way needs to be validated. In this work, we found that the distribution of DA in the digestive gland of the scallops is mostly homogeneous. Only the area closest to the gonad, and especially its outer portion, had a lower concentration than the other ones, probably due to a transfer of the toxin to the intestinal loop. Samples obtained by biopsies can therefore be considered to be representative. Most of the toxin was accumulated in large cells (mostly digestive cells), which could be due to differences during the toxin absorption or to the preferential depuration of the toxin from the small cells (mostly secretory).

ACS Style

Juan Blanco; Aida Mauríz; Gonzalo Álvarez. Distribution of Domoic Acid in the Digestive Gland of the King Scallop Pecten maximus. Toxins 2020, 12, 371 .

AMA Style

Juan Blanco, Aida Mauríz, Gonzalo Álvarez. Distribution of Domoic Acid in the Digestive Gland of the King Scallop Pecten maximus. Toxins. 2020; 12 (6):371.

Chicago/Turabian Style

Juan Blanco; Aida Mauríz; Gonzalo Álvarez. 2020. "Distribution of Domoic Acid in the Digestive Gland of the King Scallop Pecten maximus." Toxins 12, no. 6: 371.

Journal article
Published: 22 October 2019 in Toxins
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Galicia is an area with a strong mussel aquaculture industry in addition to other important bivalve mollusc fisheries. Between 2014 and 2017, 18,862 samples were analyzed for EU regulated marine lipophilic toxins. Okadaic acid (OA) was the most prevalent toxin and the only single toxin that produced harvesting closures. Toxin concentrations in raft mussels were generally higher than those recorded in other bivalves, justifying the use of this species as an indicator. The Rías of Pontevedra and Muros were the ones most affected by OA and DTX2 and the Ría of Ares by YTXs. In general, the outer areas of the Rías were more affected by OA and DTX2 than the inner ones. The OA level reached a maximum in spring, while DTX2 was almost entirely restricted to the fall–winter season. YTXs peaked in August–September. The toxins of the OA group were nearly completely esterified in all the bivalves studied except mussels and queen scallops. Risk of intoxication with the current monitoring system is low. In less than 2% of cases did the first detection of OA in an area exceed the regulatory limit. In no case, could any effect on humans be expected. The apparent intoxication and depuration rates were similar and directly related, suggesting that the rates are regulated mainly by oceanographic characteristics.

ACS Style

Juan Blanco; Fabiola Arévalo; Jorge Correa; Ángeles Moroño. Lipophilic Toxins in Galicia (NW Spain) between 2014 and 2017: Incidence on the Main Molluscan Species and Analysis of the Monitoring Efficiency. Toxins 2019, 11, 612 .

AMA Style

Juan Blanco, Fabiola Arévalo, Jorge Correa, Ángeles Moroño. Lipophilic Toxins in Galicia (NW Spain) between 2014 and 2017: Incidence on the Main Molluscan Species and Analysis of the Monitoring Efficiency. Toxins. 2019; 11 (10):612.

Chicago/Turabian Style

Juan Blanco; Fabiola Arévalo; Jorge Correa; Ángeles Moroño. 2019. "Lipophilic Toxins in Galicia (NW Spain) between 2014 and 2017: Incidence on the Main Molluscan Species and Analysis of the Monitoring Efficiency." Toxins 11, no. 10: 612.

Editorial
Published: 16 July 2019 in Toxins
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Several planktonic dinoflagellate species of the genus Dinophysis produce one or two groups of lipophilic toxins: (i) okadaic acid (OA) and its derivatives, the dinophysistoxins (DTXs), and (ii) pectenotoxins (PTXs)

ACS Style

Beatriz Reguera; Juan Blanco. Dinophysis Toxins: Distribution, Fate in Shellfish and Impacts. Toxins 2019, 11, 413 .

AMA Style

Beatriz Reguera, Juan Blanco. Dinophysis Toxins: Distribution, Fate in Shellfish and Impacts. Toxins. 2019; 11 (7):413.

Chicago/Turabian Style

Beatriz Reguera; Juan Blanco. 2019. "Dinophysis Toxins: Distribution, Fate in Shellfish and Impacts." Toxins 11, no. 7: 413.

Journal article
Published: 06 July 2019 in Toxins
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Okadaic acid (OA) and other toxins of the diarrheic shellfish poisoning (DSP) group are accumulated and transformed mainly in many bivalves, inside the digestive gland cells. In this work the absorption of okadaic acid by those cells has been studied by supplying the toxin dissolved in water and including it in oil droplets given to primary cell cultures, and by checking if the uptake is saturable and/or energy-dependent. Okadaic acid was found to be absorbed preferentially from the dissolved phase, and the uptake from oil droplets was substantially lower. The process did not require energy and was non-saturable, indicating that it involved a simple diffusion across the cellular membrane. Some apparent saturation was found due to the quick biotransformation of OA to 7-O-acyl esters.

ACS Style

Juan Blanco; Helena Martín; Carmen Mariño; Araceli Escudeiro Rossignoli. Simple Diffusion as the Mechanism of Okadaic Acid Uptake by the Mussel Digestive Gland. Toxins 2019, 11, 395 .

AMA Style

Juan Blanco, Helena Martín, Carmen Mariño, Araceli Escudeiro Rossignoli. Simple Diffusion as the Mechanism of Okadaic Acid Uptake by the Mussel Digestive Gland. Toxins. 2019; 11 (7):395.

Chicago/Turabian Style

Juan Blanco; Helena Martín; Carmen Mariño; Araceli Escudeiro Rossignoli. 2019. "Simple Diffusion as the Mechanism of Okadaic Acid Uptake by the Mussel Digestive Gland." Toxins 11, no. 7: 395.

Journal article
Published: 14 June 2019 in Toxins
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For the first time, pinnatoxins have been detected in shellfish from the Atlantic and Cantabrian coasts of Spain. High sensitivity LC-MS/MS systems were used to monitor all the currently known pinnatoxins (A–H). Pinnatoxin G (PnTX G) was the most prevalent toxin of the group, but its metabolite PnTX A has also been found at much lower levels. No trend in PnTX G concentration was found in the area, but a hotspot in the Ría de Camariñas has been identified. The maximum concentrations found did not exceed 15 µg·kg−1, being, in most cases, below 3 µg·kg−1. The highest concentrations were found in wild (intertidal) populations of mussels which attained much higher levels than raft-cultured ones, suggesting that the toxin-producer organisms preferentially develop in shallow areas. Other bivalve species had, in general, lower concentrations. The incidence of PnTX G followed a seasonal pattern in which the maximum concentrations took place in winter months. PnTX G was found to be partially esterified but the esterification percentage was not high (lower than 30%).

ACS Style

J. Pablo Lamas; Fabiola Arévalo; Ángeles Moroño; Jorge Correa; Susana Muñíz; Juan Blanco. Detection and Spatio-Temporal Distribution of Pinnatoxins in Shellfish from the Atlantic and Cantabrian Coasts of Spain. Toxins 2019, 11, 340 .

AMA Style

J. Pablo Lamas, Fabiola Arévalo, Ángeles Moroño, Jorge Correa, Susana Muñíz, Juan Blanco. Detection and Spatio-Temporal Distribution of Pinnatoxins in Shellfish from the Atlantic and Cantabrian Coasts of Spain. Toxins. 2019; 11 (6):340.

Chicago/Turabian Style

J. Pablo Lamas; Fabiola Arévalo; Ángeles Moroño; Jorge Correa; Susana Muñíz; Juan Blanco. 2019. "Detection and Spatio-Temporal Distribution of Pinnatoxins in Shellfish from the Atlantic and Cantabrian Coasts of Spain." Toxins 11, no. 6: 340.

Journal article
Published: 29 March 2019 in Toxins
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In late February 2016, a harmful algal bloom (HAB) of Alexandrium catenella was detected in southern Chiloé, leading to the banning of shellfish harvesting in an extended geographical area (~500 km). On April 24, 2016, this bloom produced a massive beaching (an accumulation on the beach surface of dead or impaired organisms which were drifted ashore) of surf clams Mesodesma donacium in Cucao Bay, Chiloé. To determine the effect of paralytic shellfish poisoning (PSP) toxins in M. donacium, samples were taken from Cucao during the third massive beaching detected on May 3, 2016. Whole tissue toxicity evidence a high interindividual variability with values which ranged from 1008 to 8763 μg STX eq 100 g−1 and with a toxin profile dominated by GTX3, GTX1, GTX2, GTX4, and neoSTX. Individuals were dissected into digestive gland (DG), foot (FT), adductor muscle (MU), and other body fractions (OBF), and histopathological and toxin analyses were carried out on the obtained fractions. Some pathological conditions were observed in gill and digestive gland of 40–50% of the individuals that correspond to hemocyte aggregation and haemocytic infiltration, respectively. The most toxic tissue was DG (2221 μg STX eq 100 g−1), followed by OBF (710 μg STX eq 100 g−1), FT (297 μg STX eq 100 g−1), and MU (314 μg STX eq 100 g−1). The observed surf clam mortality seems to have been mainly due to the desiccation caused by the incapability of the clams to burrow. Considering the available information of the monitoring program and taking into account that this episode was the first detected along the open coast of the Pacific Ocean in southern Chiloé, it is very likely that the M. donacium population from Cucao Bay has not had a recurrent exposition to A. catenella and, consequently, that it has not been subjected to high selective pressure for PSP resistance. However, more research is needed to determine the effects of PSP toxins on behavioral and physiological responses, nerve sensitivity, and genetic/molecular basis for the resistance or sensitivity of M. donacium.

ACS Style

Gonzalo Álvarez; Patricio A. Díaz; Marcos Godoy; Michael Araya; Iranzu Ganuza; Roberto Pino; Francisco Álvarez; José Rengel; Cristina Hernández; Eduardo Uribe; Juan Blanco. Paralytic Shellfish Toxins in Surf Clams Mesodesma donacium during a Large Bloom of Alexandrium catenella Dinoflagellates Associated to an Intense Shellfish Mass Mortality. Toxins 2019, 11, 188 .

AMA Style

Gonzalo Álvarez, Patricio A. Díaz, Marcos Godoy, Michael Araya, Iranzu Ganuza, Roberto Pino, Francisco Álvarez, José Rengel, Cristina Hernández, Eduardo Uribe, Juan Blanco. Paralytic Shellfish Toxins in Surf Clams Mesodesma donacium during a Large Bloom of Alexandrium catenella Dinoflagellates Associated to an Intense Shellfish Mass Mortality. Toxins. 2019; 11 (4):188.

Chicago/Turabian Style

Gonzalo Álvarez; Patricio A. Díaz; Marcos Godoy; Michael Araya; Iranzu Ganuza; Roberto Pino; Francisco Álvarez; José Rengel; Cristina Hernández; Eduardo Uribe; Juan Blanco. 2019. "Paralytic Shellfish Toxins in Surf Clams Mesodesma donacium during a Large Bloom of Alexandrium catenella Dinoflagellates Associated to an Intense Shellfish Mass Mortality." Toxins 11, no. 4: 188.

Journal article
Published: 06 February 2019 in Toxins
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Some species of the genus Pseudo-nitzschia produce the toxin domoic acid, which causes amnesic shellfish poisoning (ASP). Given that bivalve mollusks are filter feeders, they can accumulate these toxins in their tissues. To elucidate the transcriptional response of the queen scallop Aequipecten opercularis after exposure to domoic acid-producing Pseudo-nitzschia, the digestive gland transcriptome was de novo assembled using an Illumina HiSeq 2000 platform. Then, a differential gene expression analysis was performed. After the assembly, 142,137 unigenes were obtained, and a total of 10,144 genes were differentially expressed in the groups exposed to the toxin. Functional enrichment analysis found that 374 Pfam (protein families database) domains were significantly enriched. The C1q domain, the C-type lectin, the major facilitator superfamily, the immunoglobulin domain, and the cytochrome P450 were among the most enriched Pfam domains. Protein network analysis showed a small number of highly connected nodes involved in specific functions: proteasome components, mitochondrial ribosomal proteins, protein translocases of mitochondrial membranes, cytochromes P450, and glutathione S-transferases. The results suggest that exposure to domoic acid-producing organisms causes oxidative stress and mitochondrial dysfunction. The transcriptional response counteracts these effects with the up-regulation of genes coding for some mitochondrial proteins, proteasome components, and antioxidant enzymes (glutathione S-transferases, thioredoxins, glutaredoxins, and copper/zinc superoxide dismutases).

ACS Style

Pablo Ventoso; Antonio J. Pazos; M. Luz Pérez-Parallé; Juan Blanco; Juan C. Triviño; José L. Sánchez. Aequipecten opercularis) Digestive Gland after Exposure to Domoic Acid-Producing Pseudo-nitzschia. Toxins 2019, 11, 97 .

AMA Style

Pablo Ventoso, Antonio J. Pazos, M. Luz Pérez-Parallé, Juan Blanco, Juan C. Triviño, José L. Sánchez. Aequipecten opercularis) Digestive Gland after Exposure to Domoic Acid-Producing Pseudo-nitzschia. Toxins. 2019; 11 (2):97.

Chicago/Turabian Style

Pablo Ventoso; Antonio J. Pazos; M. Luz Pérez-Parallé; Juan Blanco; Juan C. Triviño; José L. Sánchez. 2019. "Aequipecten opercularis) Digestive Gland after Exposure to Domoic Acid-Producing Pseudo-nitzschia." Toxins 11, no. 2: 97.

Original research article
Published: 18 December 2018 in Frontiers in Marine Science
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Spirolides are polyether cyclic imines considered as “fast acting toxins.” Long-term human health consequences of spirolide ingestion are uncertain, and hence regulatory limits for human consumption have not been established. Nevertheless, monitoring these toxins in shellfish is essential because they can interfere with detection by mouse bioassay of lipophilic regulated toxins. Todos Santos Bay (TSB), in the northwest of the Baja California Peninsula, is an important shellfish cultivation and fish-farming area in Mexico. The toxin analog 13-desmethyl spirolide C has been reported in cultivated mussels (Mytilus galloprovincialis) from TSB, but the causative species associated with accumulation of this toxin has not been previously identified. We assessed the occurrence of Alexandrium ostenfeldii, the unique known producer of spirolides, by inverted light microscopy and by PCR with species-specific oligonucleotides designed for the ITS and 18S rDNA. We determined the presence and abundance of this species at the surface and at the thermocline from samples collected over two annual sampling periods (2013–2014 and 2016–2017). During the 2013–2014 period, A. ostenfeldii was found in 50% of the samples analyzed by light microscopy. The highest cell abundance (about 3.6 × 103 cells L-1) occurred in October 2013. During 2016–2017 the dinoflagellate was present in low cell abundances (<5 × 102 cells L-1) and was detected in only 20.9% of the samples. Cells of this species were usually found when sea surface temperature ranged from 17 to 20∘C. We also evaluated spirolide accumulated in cultivated mussels from TSB by tandem mass spectrometry (LC-MS/MS). The only spirolide detected was 13-desmethyl spirolide C, found mainly during the 2013–2014 sampling period, with the highest concentration (1.05 μg kg-1) in June 2014. During winter, toxin concentration was at or below the detection limit. During 2016–2017, spirolides were below the detection limit, coinciding with the absence of the causative species. Cell abundance of A. ostenfeldii and spirolide concentration in mussels did not present a clear correlation. This study represents the first record of A. ostenfeldii in TSB and provides evidence that this species is the primary origin of spirolides accumulated in mussels.

ACS Style

Patricia Paredes-Banda; Ernesto García-Mendoza; Elizabeth Ponce-Rivas; Juan Blanco; Antonio Almazán-Becerril; Clara Galindo-Sánchez; Allan Cembella. Association of the Toxigenic Dinoflagellate Alexandrium ostenfeldii With Spirolide Accumulation in Cultured Mussels (Mytilus galloprovincialis) From Northwest Mexico. Frontiers in Marine Science 2018, 5, 1 .

AMA Style

Patricia Paredes-Banda, Ernesto García-Mendoza, Elizabeth Ponce-Rivas, Juan Blanco, Antonio Almazán-Becerril, Clara Galindo-Sánchez, Allan Cembella. Association of the Toxigenic Dinoflagellate Alexandrium ostenfeldii With Spirolide Accumulation in Cultured Mussels (Mytilus galloprovincialis) From Northwest Mexico. Frontiers in Marine Science. 2018; 5 ():1.

Chicago/Turabian Style

Patricia Paredes-Banda; Ernesto García-Mendoza; Elizabeth Ponce-Rivas; Juan Blanco; Antonio Almazán-Becerril; Clara Galindo-Sánchez; Allan Cembella. 2018. "Association of the Toxigenic Dinoflagellate Alexandrium ostenfeldii With Spirolide Accumulation in Cultured Mussels (Mytilus galloprovincialis) From Northwest Mexico." Frontiers in Marine Science 5, no. : 1.

Review
Published: 02 November 2018 in Toxins
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Several species of the dinoflagellate genus Dinophysis produce toxins that accumulate in bivalves when they feed on populations of these organisms. The accumulated toxins can lead to intoxication in consumers of the affected bivalves. The risk of intoxication depends on the amount and toxic power of accumulated toxins. In this review, current knowledge on the main processes involved in toxin accumulation were compiled, including the mechanisms and regulation of toxin acquisition, digestion, biotransformation, compartmentalization, and toxin depuration. Finally, accumulation kinetics, some models to describe it, and some implications were also considered.

ACS Style

Juan Blanco. Accumulation of Dinophysis Toxins in Bivalve Molluscs. Toxins 2018, 10, 453 .

AMA Style

Juan Blanco. Accumulation of Dinophysis Toxins in Bivalve Molluscs. Toxins. 2018; 10 (11):453.

Chicago/Turabian Style

Juan Blanco. 2018. "Accumulation of Dinophysis Toxins in Bivalve Molluscs." Toxins 10, no. 11: 453.

Journal article
Published: 16 October 2018 in Marine Chemistry
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Persistence of lipophilic toxins in different environmental compartments determines the way in which their concentrations can be used to evaluate temporal trends and associated risks. Short term stability of two lipophilic toxins, representing two chemically different groups of toxins — okadaic acid (OA) (Diarrhetic Shellfish Poisoning toxin) and 13-desmethyl spirolide C (13desmSPXC) (cyclic imine) — in seawater, interstitial water and sediment were analyzed. OA was found to be very stable in seawater, interstitial water and sediment, without significant changes over a 23-day period. Contrarily, 13desmSPXC was readily degraded, but faster in interstitial water than in seawater. In sediments, its degradation was also fast and dependent on the origin of the samples. 13desmSPXC was found in natural sediments, and this toxin was mostly associated to large particles (>10 μm) in the sediment, that are or include resting cysts of the producer species. Therefore, it appears that high concentrations of 13desmSPXC in seawater would indicate recent blooms of the producer species, while those of OA could be due to recent blooms or to others that took place long before detection. The absence of OA and 13desmSPXC indicates a low impact of those toxins in the study area.

ACS Style

Juan Blanco; Eva Martín-Morales; Gonzalo Álvarez. Stability of okadaic acid and 13-desmethyl spirolide C in seawater and sediment. Marine Chemistry 2018, 207, 21 -25.

AMA Style

Juan Blanco, Eva Martín-Morales, Gonzalo Álvarez. Stability of okadaic acid and 13-desmethyl spirolide C in seawater and sediment. Marine Chemistry. 2018; 207 ():21-25.

Chicago/Turabian Style

Juan Blanco; Eva Martín-Morales; Gonzalo Álvarez. 2018. "Stability of okadaic acid and 13-desmethyl spirolide C in seawater and sediment." Marine Chemistry 207, no. : 21-25.

Regular article
Published: 08 October 2018 in Journal of Phycology
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Dinoflagellates of the genus Dinophysis are the most persistent producers of lipophilic shellfish toxins in western Europe. Their mixotrophic nutrition requires a food‐chain of cryptophytes and plastid‐bearing ciliates for sustained growth and photosynthesis. In this study, cultures of D. acuminata and D. acuta, their ciliate prey Mesodinium rubrum and the cryptophyte, Teleaulax amphioxeia, were subject to three experimental settings to study their physiological response to different combinations of light intensity and quality. Growth rates, pigment analyses (HPLC), photosynthetic parameters (PAM‐fluorometry) and cellular toxin content (LC‐MS) were determined. Specific differences in photosynthetic parameters were observed in Dinophysis exposed to different photon fluxes (10‐650 μmol photons · m−2 · s−1), light quality (white, blue and green) and shifts in light regime. Dinophysis acuta was more susceptible to photodamage under high light intensities (370‐650 μmol photons · m−2· s−1) than D. acuminata but survived better with low light (10 μmol photons · m−2 · s−1) and to a prolonged period (28 d) of darkness. Mesodinium rubrum and T. amphioxeia showed their maximal growth rate and yield under white and high light whereas Dinophysis seemed better adapted to grow under green and blue. Toxin analyses in Dinophysis showed maximal toxin per cell under high light after prey depletion at the late exponential‐plateau phase. Changes observed in photosynthetic light curves of D. acuminata cultures after shifting light conditions from low intensity‐blue light to high intensity‐white light seemed compatible with photoacclimation in this species. Results obtained here are discussed in relation to different spatio‐temporal distributions observed in field populations of D. acuminata and D. acuta in northwestern Iberia. This article is protected by copyright. All rights reserved.

ACS Style

María García-Portela; Pilar Riobó; Beatriz Reguera; José Luis Garrido; Juan Blanco; Francisco Rodríguez. Comparative ecophysiology of Dinophysis acuminata and D. acuta (DINOPHYCEAE, DINOPHYSIALES): effect of light intensity and quality on growth, cellular toxin content, and photosynthesis. Journal of Phycology 2018, 54, 899 -917.

AMA Style

María García-Portela, Pilar Riobó, Beatriz Reguera, José Luis Garrido, Juan Blanco, Francisco Rodríguez. Comparative ecophysiology of Dinophysis acuminata and D. acuta (DINOPHYCEAE, DINOPHYSIALES): effect of light intensity and quality on growth, cellular toxin content, and photosynthesis. Journal of Phycology. 2018; 54 (6):899-917.

Chicago/Turabian Style

María García-Portela; Pilar Riobó; Beatriz Reguera; José Luis Garrido; Juan Blanco; Francisco Rodríguez. 2018. "Comparative ecophysiology of Dinophysis acuminata and D. acuta (DINOPHYCEAE, DINOPHYSIALES): effect of light intensity and quality on growth, cellular toxin content, and photosynthesis." Journal of Phycology 54, no. 6: 899-917.

Journal article
Published: 04 August 2018 in Toxins
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Surf clams, Mesodesma donacium, were shown to accumulate toxins from Dinophysis acuminata blooms. Only pectenotoxin 2 (PTX2) and some of its derivatives were found, and no toxins from the okadaic acid group were detected. PTX2 seems to be transformed to PTX2 seco-acid (PTX2sa), which was found in concentrations more than ten-fold those of PTX2. The seco-acid was transformed to acyl-derivatives by esterification with different fatty acids. The estimated amount of these derivatives in the mollusks was much higher than that of PTX2. Most esters were originated by even carbon chain fatty acids, but some originated by odd carbon number were also found in noticeable concentrations. Some peaks of toxin in the bivalves did not coincide with those of Dinophysis abundance, suggesting that there were large differences in toxin content per cell among the populations that developed throughout the year. The observed depuration (from the digestive gland) was fast (more than 0.2 day−1), and was faster for PTX2 than for PTX2sa, which in turn was faster than that of esters of PTX2sa. PTX2 and PTX2sa were distributed nearly equally between the digestive gland and the remaining tissues, but less than 5% of the palmytoyl-esters were found outside the digestive gland.

ACS Style

Juan Blanco; Gonzalo Álvarez; José Rengel; Rosario Díaz; Carmen Mariño; Helena Martín; Eduardo Uribe. Accumulation and Biotransformation of Dinophysis Toxins by the Surf Clam Mesodesma donacium. Toxins 2018, 10, 314 .

AMA Style

Juan Blanco, Gonzalo Álvarez, José Rengel, Rosario Díaz, Carmen Mariño, Helena Martín, Eduardo Uribe. Accumulation and Biotransformation of Dinophysis Toxins by the Surf Clam Mesodesma donacium. Toxins. 2018; 10 (8):314.

Chicago/Turabian Style

Juan Blanco; Gonzalo Álvarez; José Rengel; Rosario Díaz; Carmen Mariño; Helena Martín; Eduardo Uribe. 2018. "Accumulation and Biotransformation of Dinophysis Toxins by the Surf Clam Mesodesma donacium." Toxins 10, no. 8: 314.

Journal article
Published: 01 November 2017 in Toxicon
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The toxin profile and hemolytic activity of a strain of Ostreopsis cf. ovata (UFBA013) isolated from Todos os Santos Bay (northeastern Brazil) were evaluated under different levels of N and P. Phylogenetic analyses based on ITS rDNA region (ITS1-5.8S-ITS2) placed UFBA013 within the Atlantic/Mediterranean/Pacific clade of O. cf. ovata. Growth experiments were conducted in f/2 medium modified by adding N and P (P: 0-36 μM; N: 0-882 μM). The growth kinetics was adequately described by logistic equations. The best growth (highest Gm) was recorded under levels of N/P = 0/18, 129/5 and 441/36, while one of the lowest Gm was obtained under P-depletion. The maximum and specific maximum growth rates (as vm; cells mL(-1) d(-1) and μm; d(-1)) were achieved with N limitation (N/P = 441/36) and P-limitation/depletion (753/5.3 and 441/0) and are the highest values reported in the literature, most similar to isolates from Pacific and Mediterranean areas. The control experiment (N/P = 441/18) also yielded similar values to those from some Mediterranean isolates, but higher than formerly reported for Brazilian isolates. In all conditions assayed, no palytoxin (PLTX) was detected. The ovatoxins (OVTXs) a, b, c, d and e did not show significant differences in cell quota between exponential and stationary phases. A significant relationship was detected between OVTXs concentration and hemolytic activity.

ACS Style

Maria Cristina De Q. Mendes; José Marcos C. Nunes; Mariângela Menezes; Santiago Fraga; Francisco Rodriguez; José A. Vázquez; Juan Blanco; José M. Franco; Pilar Riobó. Toxin production, growth kinetics and molecular characterization of Ostreopsis cf. ovata isolated from Todos os Santos Bay, tropical southwestern Atlantic. Toxicon 2017, 138, 18 -30.

AMA Style

Maria Cristina De Q. Mendes, José Marcos C. Nunes, Mariângela Menezes, Santiago Fraga, Francisco Rodriguez, José A. Vázquez, Juan Blanco, José M. Franco, Pilar Riobó. Toxin production, growth kinetics and molecular characterization of Ostreopsis cf. ovata isolated from Todos os Santos Bay, tropical southwestern Atlantic. Toxicon. 2017; 138 ():18-30.

Chicago/Turabian Style

Maria Cristina De Q. Mendes; José Marcos C. Nunes; Mariângela Menezes; Santiago Fraga; Francisco Rodriguez; José A. Vázquez; Juan Blanco; José M. Franco; Pilar Riobó. 2017. "Toxin production, growth kinetics and molecular characterization of Ostreopsis cf. ovata isolated from Todos os Santos Bay, tropical southwestern Atlantic." Toxicon 138, no. : 18-30.

Journal article
Published: 01 October 2017 in Toxicon
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Low concentrations of azaspiracids have been found in bivalve molluscs all over the Northern and Northwestern coast of the Iberian Peninsula. The detections started in June 2016 and lasted until March 2017. The observed toxin profile was dominated by AZA2, followed by AZA1 and some other AZAs that were detected only in some samples. Some compounds producing fragments characteristics of AZAs but that do not fit with any of the known ones were also found. The causative agent has not been identified but, in sight of the toxin profile in the bivalves, it seems that it should be a new species or strain. The detections of AZAs in bivalves in the Northern Coast was linked to downwelling or upwelling relaxation and, in the Galician Rías, took place (with only a few exceptions) in the outer (more oceanic) part, suggesting that the responsible species develops at the open sea and that the populations are advected to the shore.

ACS Style

Juan Blanco; Fabiola Arévalo; Ángeles Moroño; Jorge Correa; Susana Muñíz; Carmen Mariño; Helena Martín. Presence of azaspiracids in bivalve molluscs from Northern Spain. Toxicon 2017, 137, 135 -143.

AMA Style

Juan Blanco, Fabiola Arévalo, Ángeles Moroño, Jorge Correa, Susana Muñíz, Carmen Mariño, Helena Martín. Presence of azaspiracids in bivalve molluscs from Northern Spain. Toxicon. 2017; 137 ():135-143.

Chicago/Turabian Style

Juan Blanco; Fabiola Arévalo; Ángeles Moroño; Jorge Correa; Susana Muñíz; Carmen Mariño; Helena Martín. 2017. "Presence of azaspiracids in bivalve molluscs from Northern Spain." Toxicon 137, no. : 135-143.

Journal article
Published: 01 October 2017 in Aquaculture
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ACS Style

Juan Blanco; Helena Martín; Carmen Mariño. Reduction of diarrhetic shellfish poisoning (DSP) toxins accumulation in cultured mussels by means of rope clustering and hydrodynamic barriers. Aquaculture 2017, 479, 120 -124.

AMA Style

Juan Blanco, Helena Martín, Carmen Mariño. Reduction of diarrhetic shellfish poisoning (DSP) toxins accumulation in cultured mussels by means of rope clustering and hydrodynamic barriers. Aquaculture. 2017; 479 ():120-124.

Chicago/Turabian Style

Juan Blanco; Helena Martín; Carmen Mariño. 2017. "Reduction of diarrhetic shellfish poisoning (DSP) toxins accumulation in cultured mussels by means of rope clustering and hydrodynamic barriers." Aquaculture 479, no. : 120-124.