scholarly journals Reconocimiento de dos variedades taxonómicas de Pyrodinium bahamense (Gonyaulacales, Dinophyceae): var. bahamense y var. compressum

2022 ◽  
Author(s):  
María Eugenia Zamudio Resendiz ◽  
Alexis de Jesús Escarcega Bata ◽  
María Luisa Núñez Resendiz ◽  
María Esther Meave del Castillo
Keyword(s):  
Pyrodinium Bahamense

Antecedentes y Objetivos: Pyrodinium es un género monotípico con dos variedades, var. bahamense en el Atlántico, no tóxica, y var. compressum en el Indo-Pacífico y tóxica. Hallazgos recientes de toxicidad por envenenamiento paralitico por mariscos (PSP), en poblaciones de P. bahamense var. bahamense, debilitaron el interés por aceptarlas como independientes, e incluso investigar la posibilidad de cripticismo. En los pocos estudios que han incorporado evidencia molecular en el tratamiento de las variedades, su independencia taxonómica sigue siendo negada, a pesar de la evidente y consistente separación genética presentada en todos los análisis. Por lo tanto, el objetivo de este estudio fue reconocer, desde la evidencia genética, la independencia taxonómica de las dos variedades de Pyrodinium: P. bahamense var. compressum y var. bahamense. Métodos: A partir de tres marcadores moleculares (Lcf, LSU, SSU) de secuencias disponibles en el Genbank, se construyeron redes de parsimonia estadística y un análisis filogenético concatenado. Resultados clave: En todos los análisis, se obtuvo de manera consistente una estructura genética para P. bahamense var. bahamense y otra para P. bahamense var. compressum. Además, la correspondencia de haplotipos y ribotipos resultantes fue siempre la misma, tanto en redes como en la filogenia; es decir, las muestras del Océano Pacífico siempre se colocaron en un grupo distinto al de las secuencias del Océano Atlántico. Conclusiones: La evidencia proporcionada en este estudio demostró que existe un aislamiento reproductivo entre ambas variedades, e incluso la posible presencia de una tercera variedad aún no descrita, por lo cual proponemos la validez e independencia taxonómica de P. bahamense var. compressum y P. bahamense var. bahamense.

scholarly journals sxtA4+ and sxtA4- Genotypes Occur Together within Natural Pyrodinium bahamense Sub-Populations from the Western Atlantic

2021 ◽  
Vol 9 (6) ◽  
pp. 1128
Author(s):  
Kathleen Cusick ◽  
Gabriel Duran
Keyword(s):  
Molecular Mechanisms ◽  
Harmful Algal Bloom ◽  
Single Cells ◽  
Natural Populations ◽  
Indian River Lagoon ◽  
Toxin Production ◽  
Genotype Frequency ◽  
Rrna Gene ◽  
Western Atlantic ◽  
Pyrodinium Bahamense

Saxitoxin (STX) is a secondary metabolite and potent neurotoxin produced by several genera of harmful algal bloom (HAB) marine dinoflagellates. The basis for variability in STX production within natural bloom populations is undefined as both toxic and non-toxic strains (of the same species) have been isolated from the same geographic locations. Pyrodinium bahamense is a STX-producing bioluminescent dinoflagellate that blooms along the east coast of Florida as well as the bioluminescent bays in Puerto Rico (PR), though no toxicity reports exist for PR populations. The core genes in the dinoflagellate STX biosynthetic pathway have been identified, and the sxtA4 gene is essential for toxin production. Using sxtA4 as a molecular proxy for the genetic capacity of STX production, we examined sxtA4+ and sxtA4- genotype frequency at the single cell level in P. bahamense populations from different locations in the Indian River Lagoon (IRL), FL, and Mosquito Bay (MB), a bioluminescent bay in PR. Multiplex PCR was performed on individual cells with Pyrodinium-specific primers targeting the 18S rRNA gene and sxtA4. The results reveal that within discrete natural populations of P. bahamense, both sxtA4+ and sxtA4- genotypes occur, and the sxtA4+ genotype dominates. In the IRL, the frequency of the sxtA4+ genotype ranged from ca. 80–100%. In MB, sxtA4+ genotype frequency ranged from ca 40–66%. To assess the extent of sxtA4 variation within individual cells, sxtA4 amplicons from single cells representative of the different sampling sites were cloned and sequenced. Overall, two variants were consistently obtained, one of which is likely a pseudogene based on alignment with cDNA sequences. These are the first data demonstrating the existence of both genotypes in natural P. bahamense sub-populations, as well as sxtA4 presence in P. bahamense from PR. These results provide insights on underlying genetic factors influencing the potential for toxin variability among natural sub-populations of HAB species and highlight the need to study the genetic diversity within HAB sub-populations at a fine level in order to identify the molecular mechanisms driving HAB evolution.

Predicting Pyrodinium bahamense occurrence using weather pattern data in Eastern Visayas, Philippines

2021 ◽  
Vol 193 (9) ◽  
Author(s):  
Angelica Joy G. Yu ◽  
Noel B. Elizaga ◽  
Richard B. Parilla ◽  
Eulito V. Casas ◽  
Juan D. Albaladejo
Keyword(s):  
Weather Pattern ◽  
Pyrodinium Bahamense

scholarly journals Physiological characteristics of two varieties of Pyrodinium bahamense

2002 ◽  
Vol 68 (sup1) ◽  
pp. 523-524
Author(s):  
TAKUO OMURA ◽  
TAKASHI ISHIMARU ◽  
YASUWO FUKUYO
Keyword(s):  
Physiological Characteristics ◽  
Pyrodinium Bahamense

scholarly journals High-Resolution Spatiotemporal Dynamics of Harmful Algae in the Indian River Lagoon (Florida)—A Case Study of Aureoumbra lagunensis, Pyrodinium bahamense, and Pseudo-nitzschia

2021 ◽  
Vol 8 ◽  
Author(s):  
Cary B. Lopez ◽  
Charles L. Tilney ◽  
Eric Muhlbach ◽  
Josée N. Bouchard ◽  
Maria Célia Villac ◽  
...  
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Seasonal Pattern ◽  
Indian River Lagoon ◽  
Early Summer ◽  
Temperature Cycle ◽  
Estuarine Ecosystem ◽  
Indian River ◽  
Pyrodinium Bahamense ◽  
Aureoumbra Lagunensis

The Indian River Lagoon (IRL), located on the east coast of Florida, is a complex estuarine ecosystem that is negatively affected by recurring harmful algal blooms (HABs) from distinct taxonomic/functional groups. Enhanced monitoring was established to facilitate rapid quantification of three recurrent bloom taxa, Aureoumbra lagunensis, Pyrodinium bahamense, and Pseudo-nitzschia spp., and included corroborating techniques to improve the identification of small-celled nanoplankton (<10 μm in diameter). Identification and enumeration of these target taxa were conducted during 2015–2020 using a combination of light microscopy and species-specific approaches, specifically immunofluorescence flow cytometry as well as a newly developed qPCR assay for A. lagunensis presented here for the first time. An annual bloom index (ABI) was established for each taxon based on occurrence and abundance data. Blooms of A. lagunensis (>2 × 108 cells L–1) were observed in all 6 years sampled and across multiple seasons. In contrast, abundance of P. bahamense, largely driven by the annual temperature cycle that moderates life cycle transitions and growth, displayed a strong seasonal pattern with blooms (105–107 cells L–1) generally developing in early summer and subsiding in autumn. However, P. bahamense bloom development was delayed and abundance was significantly lower in years and locations with sustained A. lagunensis blooms. Pseudo-nitzschia spp. were broadly distributed with sporadic bloom concentrations (reaching 107 cells L–1), but with minimal concentrations of the toxin domoic acid detected (<0.02 μg L–1). In summer 2020, multiple monitoring tools characterized a novel nano-cyanobacterium bloom (reaching 109 cells L–1) that coincided with a decline in A. lagunensis and persisted into autumn. Statistical and time-series analyses of this spatiotemporally intensive dataset highlight prominent patterns in variability for some taxa, but also identify challenges of characterizing mechanisms underlying more episodic yet persistent events. Nevertheless, the intersect of temperature and salinity as environmental proxies proved to be informative in delineating niche partitioning, not only in the case of taxa with long-standing data sets but also for seemingly unprecedented blooms of novel nanoplanktonic taxa.

scholarly journals Síndrome de envenenamiento paralizante por consumo de moluscos

2006 ◽  
Vol 17 (1) ◽  
pp. 45-60 ◽  
Author(s):  
Martha L Hernández-Orozco ◽  
Ismael Gárate-Lizárraga
Keyword(s):  
El Sistema ◽  
Pyrodinium Bahamense ◽  
Gymnodinium Catenatum

El envenenamiento paralizante por consumo de moluscos (EPM) es un síndrome neurotóxico asociado a la presencia de saxitoxina (STX) y sus más de 26 análogos en los mariscos marinos. Las toxinas son producidas por diversas especies de dinoflagelados del género Alexandrium, Pyrodinium bahamense var. compresum y Gymnodinium catenatum, así como en algunas especies de cianobacterias. La sintomatología ocasionada por la saxitoxina y sus derivados se centra principalmente en el sistema nervioso, ya que al bloquear los canales de sodio produce parálisis; puede ser tan leve como adormecimiento de labios hasta la muerte por falla ventilatoria. El diagnóstico debe realizarse clínicamente y corroborando la toxina por medio de un bioensayo en ratón o el aislamiento en los organismos productores. No existe antídoto alguno, el tratamiento es sintomático enfocado a mantener la mecánica ventilatoria. En nuestro país se han observado brotes tóxicos en ambos litorales, sin embargo, existen pocos programas de inspección y monitoreo. La incidencia de episodios tóxicos, así como la presencia de toxinas paralizantes se ha incrementado y se ha reportado en lugares en donde antes no era común por esta razón, consideramos importante el divulgar este tipo de intoxicaciones, ya que representan un gran riesgo para la salud humana.

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