Probing the Energetic Metabolism of Resting Cysts under Different Conditions from Molecular and Physiological Perspectives in the Harmful Algal Blooms-Forming Dinoflagellate Scrippsiella trochoidea

Energetic metabolism is essential in maintaining the viability of all organisms. Resting cysts play important roles in the ecology of dinoflagellates, particularly for harmful algal blooms (HABs)-causative species. However, the energetic metabolism underlying the germination potency maintenance of resting cysts of dinoflagellate have been extremely scarce in studies from physiological and, particularly, molecular perspectives. Therefore, we used the cosmopolitan Scrippsiella trochoidea as a representative of HABs-forming and cyst-producing dinoflagellates in this work to obtain novel insights into the molecular mechanisms, regulating the energetic metabolism in dinoflagellate resting cysts, under different physical condition. As the starting step, we established a cDNA subtractive library via suppression subtractive hybridization (SSH) technology, from which we screened an incomplete sequence for the β subunit of ATP synthase gene (β-F1-ATPase), a key indicator for the status of cell’s energetic metabolism. The full-length cDNA of β-F1-ATPase gene from S.trochoidea (Stβ-F1-ATPase) was then obtained via rapid amplification of cDNA ends (RACE) (Accession: MZ343333). Our real-time qPCR detections, in vegetative cells and resting cysts treated with different physical conditions, revealed that (1) the expression of Stβ-F1-ATPase in resting cysts was generally much lower than that in vegetative cells, and (2) the Stβ-F1-ATPase expressions in the resting cysts under darkness, lowered temperature, and anoxia, and during an extended duration of dormancy, were significantly lower than that in cysts under the condition normally used for culture-maintaining (a 12 h light:12 h dark cycle, 21 °C, aerobic, and newly harvested). Our detections of the viability (via Neutral Red staining) and cellular ATP content of resting cysts, at the conditions corresponding to the abovementioned treatments, showed that both the viability and ATP content decreased rapidly within 12 h and then maintained at low levels within the 4-day experimentation under all the three conditions applied (4 °C, darkness, and anoxia), which are well in accordance with the measurements of the transcription of Stβ-F1-ATPase. These results demonstrated that the energy consumption of resting cysts reaches a low, but somehow stable, level within a short time period and is lower at low temperature, darkness, and anoxia than that at ambient temperature. Our work provides an important basis for explaining that resting cysts survive long-term darkness and low temperature in marine sediments from molecular and physiological levels.

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Mapping the Distribution of Cysts from the Toxic Dinoflagellate Cochlodinium polykrikoides in Bloom-Prone Estuaries by a Novel FluorescenceIn SituHybridization Assay

Applied and Environmental Microbiology ◽

10.1128/aem.03457-15 ◽

2015 ◽

Vol 82 (4) ◽

pp. 1114-1125 ◽

Cited By ~ 10

Author(s):

Theresa K. Hattenrath-Lehmann ◽

Yu Zhen ◽

Ryan B. Wallace ◽

Ying-Zhong Tang ◽

Christopher J. Gobler

Keyword(s):

Harmful Algal Blooms ◽

Algal Blooms ◽

Large Subunit ◽

Cross Reactivity ◽

Epifluorescence Microscopy ◽

Lsu Rdna ◽

Cochlodinium Polykrikoides ◽

Content Type ◽

Ecosystem Studies ◽

Resting Cysts

ABSTRACTCochlodinium polykrikoidesis a cosmopolitan dinoflagellate that is notorious for causing fish-killing harmful algal blooms (HABs) across North America and Asia. While recent laboratory and ecosystem studies have definitively demonstrated thatCochlodiniumforms resting cysts that may play a key role in the dynamics of its HABs, uncertainties regarding cyst morphology and detection have prohibited even a rudimentary understanding of the distribution ofC. polykrikoidescysts in coastal ecosystems. Here, we report on the development of a fluorescencein situhybridization (FISH) assay using oligonucleotide probes specific for the large subunit (LSU) ribosomal DNA (rDNA) ofC. polykrikoides. The LSU rDNA-targeted FISH assay was used with epifluorescence microscopy and was iteratively refined to maximize the fluorescent reaction withC. polykrikoidesand minimize cross-reactivity. The final LSU rDNA-targeted FISH assay was found to quantitatively recover cysts made by North American isolates ofC. polykrikoidesbut not cysts formed by other common cyst-forming dinoflagellates. The method was then applied to identify and mapC. polykrikoidescysts across bloom-prone estuaries. Annual cyst and vegetative cell surveys revealed that elevated densities ofC. polykrikoidescysts (>100 cm−3) during the spring of a given year were spatially consistent with regions of dense blooms the prior summer. The identity of cysts in sediments was confirmed via independent amplification ofC. polykrikoidesrDNA. This study mappedC. polykrikoidescysts in a natural marine setting and indicates that the excystment of cysts formed by this harmful alga may play a key role in the development of HABs of this species.

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Dinoflagellate resting cysts in recent marine sediments from the Gulf of Gemlik (Marmara Sea, Turkey) and seasonal harmful algal blooms

Phycologia ◽

10.2216/15-93.1 ◽

2016 ◽

Vol 55 (2) ◽

pp. 187-209 ◽

Cited By ~ 10

Author(s):

Neslihan Balkis ◽

Muharrem Balci ◽

Antonia Giannakourou ◽

Amalia Venetsanopoulou ◽

Petra Mudie

Keyword(s):

Marine Sediments ◽

Harmful Algal Blooms ◽

Algal Blooms ◽

Marmara Sea ◽

Resting Cysts

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Transcriptional Responses of the Heat Shock Protein 20 (Hsp20) and 40 (Hsp40) Genes to Temperature Stress and Alteration of Life Cycle Stages in the Harmful Alga Scrippsiella trochoidea (Dinophyceae)

Biology ◽

10.3390/biology9110408 ◽

2020 ◽

Vol 9 (11) ◽

pp. 408

Author(s):

Yunyan Deng ◽

Zhangxi Hu ◽

Lixia Shang ◽

Zhaoyang Chai ◽

Ying Zhong Tang

Keyword(s):

Heat Shock ◽

Heat Shock Protein ◽

Harmful Algal Blooms ◽

Algal Blooms ◽

Temperature Tolerance ◽

Intrinsic Stress ◽

Transcriptional Responses ◽

Mrna Accumulation ◽

Scrippsiella Trochoidea ◽

Resting Cyst

The small heat shock protein (sHsp) and Hsp40 are Hsp members that have not been intensively investigated but are functionally important in most organisms. In this study, the potential roles of a Hsp20 (StHsp20) and a Hsp40 (StHsp40) in dinoflagellates during adaptation to temperature fluctuation and alteration of different life stages were explored using the representative harmful algal blooms (HABs)-causative dinoflagellate species, Scrippsiella trochoidea. We isolated the full-length cDNAs of the two genes via rapid amplification of cDNA ends (RACE) and tracked their differential transcriptions via real-time qPCR. The results revealed StHsp20 and StHsp40 exhibited mRNA accumulation patterns that were highly similar in response to heat stress but completely different toward cold stress, which implies that the mechanisms underlying thermal and cold acclimation in dinoflagellates are regulated by different sets of genes. The StHsp20 was probably related to the heat tolerance of the species, and StHsp40 was closely involved in the adaptation to both higher and lower temperature fluctuations. Furthermore, significantly higher mRNA abundance of StHsp40 was detected in newly formed resting cysts, which might be a response to intrinsic stress stemmed from encystment. This finding also implied StHsp40 might be engaged in resting cyst formation of S. trochoidea. Our findings enriched the knowledge about possible cross-talk of different Hsp members in dinoflagellates and provided clues to further explore the molecular underpinnings underlying resting cyst production and broad temperature tolerance of this group of HABs contributors.

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VARIACIÓN NICTEMERAL DE LA COMUNIDAD FITOPLANCTÓNICA Y SU RELACIÓN CON LAS ESPECIES FORMADORAS DE FLORECIMIENTOS ALGALES NOCIVOS EN LA BOCA DE LA LAGUNA COSTERA DE SONTECOMAPAN, VERACRUZ, MÉXICO

CICIMAR Oceánides ◽

10.37543/oceanides.v26i1.92 ◽

2011 ◽

Vol 26 (1) ◽

pp. 19

Author(s):

R. E. Muciño-Márquez ◽

M. G. Figueroa-Torres ◽

A. Esquivel-Herrera

Keyword(s):

Environmental Variables ◽

Harmful Algal Blooms ◽

Algal Blooms ◽

Phytoplankton Community ◽

Circadian Variation ◽

Circadian Cycle ◽

Phytoplankton Species ◽

Dominance Index ◽

Scrippsiella Trochoidea ◽

The Relationship

Se determinó la estructura de la comunidad fitoplanctónica a lo largo de un ciclo nictemeral y su relación con las especies que forman Floraciones Algales Nocivas (FAN), en la boca de la laguna costera de Sontecomapan, Veracruz, durante los días 27 y 28 de octubre de 1999. Se recolectaron muestras de agua cada dos horas con una botella van Dorn para medir la temperatura, la salinidad, el pH, el oxígeno disuelto, la composición y la abundancia de la comunidad fitoplanctónica y se revisó el comportamiento de flujo y reflujo de la marea. Para describir el comportamiento de la comunidad se calculó el índice de dominancia simple, el de diversidad de Shannon (H´), equidad de Pielou (J`) y para comprender la relación de la abundancia de las especies del fitoplancton y las variables ambientales se aplicó un análisis de correspondencia canónica. Los resultados mostraron un total de 179 taxa, de los cuales 27 han sido reportadas como formadores de FAN en otros lugares. Los valores máximos de H´ = 5.8, J`= 0.9 se reportaron A las 11:00 horas de los días 27 y 28 y los mínimos de H´ = 3.79, J`= 0.6, a las 15:00 y las 23:00 horas del día 27. Con el índice de dominancia simple se determinó que Fragilaria exigua, F. tenuicollis, F. ulna var. ulna, Prorocentrum gracile y Scrippsiella trochoidea, fueron dominantes en el ciclo nictemeral. Cabe señalar que la salinidad fue la variable ambiental que más influyó en la composición y abundancia de la comunidad fitoplanctónica. Circadian variation of the phytoplankton community and its relationship to the species forming harmful algal blooms in the mouth of Sontecomapan coastal la- goon, Veracruz, Mexico We determined the structure of the phytoplankton community along a circadian cycle and its relation to species Harmful Algae Species (HAB), at the mouth of the coastal lagoon, Sontecomapan Veracruz, during the 27th and 28th of October, 1999. Water samples were collected every two hours employing a van Dorn bottle, to measure temperature, salinity, pH, dissolved oxygen, the composition and abundance of phytoplankton community and reviewed the behavior of ebb and flow of tides. In order to describe the behavior of the community the following criteria were used: simple dominance index, the Shannon diversity (H ‘), the Pielou equity (J`) and a canonical correspondence analysis was applied to understand the relationship between the abundance of phytoplankton species and environmental variables. The results showed a total of 179 taxa, 27 of which form HAB elsewhere. At 11:00 hours on October 27 and 28 maximum values of H ‘= 5.8, J`= 0.9 are reported, the minimum of H’= 3.79, J`= 0.6 at 15:00 and 23:00 hours on October 27. With simple dominance index it was determined that Fragilaria exigua, F. tenuicollis, F. ulna var. ulna, Prorocentrum gracile, and Scrippsiella trochoidea, were dominant in the circadian cycle. It should be noted that salinity was the environmental factor which most influenced the composition and abundance of phytoplankton community.

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Expression Patterns of the Heat Shock Protein 90 (Hsp90) Gene Suggest Its Possible Involvement in Maintaining the Dormancy of Dinoflagellate Resting Cysts

International Journal of Molecular Sciences ◽

10.3390/ijms222011054 ◽

2021 ◽

Vol 22 (20) ◽

pp. 11054

Author(s):

Yunyan Deng ◽

Fengting Li ◽

Zhangxi Hu ◽

Caixia Yue ◽

Ying Zhong Tang

Keyword(s):

Heat Shock ◽

Heat Shock Protein ◽

Harmful Algal Blooms ◽

Algal Blooms ◽

Life Stage ◽

Expression Patterns ◽

Heat Shock Protein 90 ◽

Model Organisms ◽

Cyst Production ◽

Resting Cysts

Heat shock protein 90 (Hsp90) is a highly conserved molecular chaperone functioning in cellular structural folding and conformational integrity maintenance and thus plays vital roles in a variety of biological processes. However, many aspects of these functions and processes remain to be fully elucidated, particularly for non-model organisms. Dinoflagellates are a group of eukaryotes that are exceedingly important in primary production and are responsible for the most harmful algal blooms (HABs) in aquatic ecosystems. The success of dinoflagellates in dominating the plankton community is undoubtedly pertinent to their remarkable adaptive strategies, characteristic of resting cyst production and broad tolerance to stresses of temperature and others. Therefore, this study was conducted to examine the putative roles of Hsp90 in the acclimation to temperature stress and life stage alterations of dinoflagellates. Firstly, we isolated the full-length cDNA of an Hsp90 gene (StHsp90) via RACE from the cosmopolitan HAB species Scrippsiella trochoidea and tracked its transcriptions in response to varied scenarios via real-time qPCR. The results indicated that StHsp90 displayed significant mRNA augment patterns, escalating during 180-min treatments, when the cells were exposed to elevated and lowered temperatures. Secondly, we observed prominently elevated StHsp90 transcriptions in the cysts that were stored at the cold and dark conditions compared to those in newly formed resting cysts and vegetative cells. Finally, and perhaps most importantly, we identified 29 entries of Hsp90-encoding genes with complete coding regions from a dinoflagellate-specific environmental cDNA library generated from marine sediment assemblages. The observed active transcription of these genes in sediment-buried resting cysts was fully supported by the qPCR results for the cold-stored resting cysts of S. trochoidea. Hsp90s expressions in both laboratory-raised and field-collected cysts collectively highlighted the possible involvement and engagement of Hsp90 chaperones in the resting stage persistence of dinoflagellates.

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Dinoflagellate cysts in surface sediments at Van Phong Bay, Khanh Hoa Province, Vietnam: distribution, abundance and potentially harmful algal blooms

ACADEMIA JOURNAL OF BIOLOGY ◽

10.15625/2615-9023/15404 ◽

2021 ◽

Vol 43 (1) ◽

Author(s):

Phan Tan Luom ◽

Doan Nhu Hai ◽

Nguyen Ngoc Lam

Keyword(s):

Harmful Algal Blooms ◽

Algal Blooms ◽

Surface Sediments ◽

Diversity Index ◽

Dry Weight ◽

The Other ◽

Dinoflagellate Cysts ◽

Toxic Dinoflagellate ◽

Scrippsiella Trochoidea ◽

Different Types

Studies on dinoflagellate cysts provide important knowledge on the ecology of dinoflagellates and harmful algal blooms (HABs). In this study, distribution and abundance of dinoflagellate cysts in surface sediments from 17 stations at Van Phong Bay were analyzed. There were 55 different types of cysts representing 3 orders and 18 genera, and 8 unidentified cyst types recorded. Peridiniales was the most diverse order with 29 cyst types, including 20 Protoperidinium cyst types. There were 10 cyst types of 7 potential toxic dinoflagellate species and 4 of bloom forming species found, indicating a potential risk of harmful algal blooms in Van Phong Bay. Number of cyst types and density ranged from 12 to 31 types and from 115 to 3,760 per gram of dry weight sediment, respectively. Cysts of Leonella granifera were dominant at stations in the mouth of the Bay, while Scrippsiella trochoidea cysts dominated at all stations. Shannon diversity index (H') was low, varying from 1.192.72. There were two distinct cyst assemblages identified with 40% Bray-Curtis similarity, assemblage I with 2 stations (VP09 and VP10), and assemblage II with the other stations.

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255. Public Health Response to Harmful Algal Blooms

10.3320/1.2765781 ◽

2001 ◽

Author(s):

P. Webb

Keyword(s):

Public Health ◽

Harmful Algal Blooms ◽

Algal Blooms ◽

Public Health Response ◽

Health Response

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National coastal management challenges and needs

Shore & Beach ◽

10.34237/1008843 ◽

2020 ◽

pp. 34-43

Author(s):

Nicole Elko ◽

Tiffany Roberts Briggs

Keyword(s):

Coastal Management ◽

Harmful Algal Blooms ◽

Algal Blooms ◽

Local Community ◽

Extreme Event ◽

Technical Information ◽

Interdisciplinary Approach ◽

Beach Erosion ◽

The U.S

In partnership with the U.S. Geological Survey Coastal and Marine Hazards and Resources Program (USGS CMHRP) and the U.S. Coastal Research Program (USCRP), the American Shore and Beach Preservation Association (ASBPA) has identified coastal stakeholders’ top coastal management challenges. Informed by two annual surveys, a multiple-choice online poll was conducted in 2019 to evaluate stakeholders’ most pressing problems and needs, including those they felt most ill-equipped to deal with in their day-to-day duties and which tools they most need to address these challenges. The survey also explored where users find technical information and what is missing. From these results, USGS CMHRP, USCRP, ASBPA, and other partners aim to identify research needs that will inform appropriate investments in useful science, tools, and resources to address today’s most pressing coastal challenges. The 15-question survey yielded 134 complete responses with an 80% completion rate from coastal stakeholders such as local community representatives and their industry consultants, state and federal agency representatives, and academics. Respondents from the East, Gulf, West, and Great Lakes coasts, as well as Alaska and Hawaii, were represented. Overall, the prioritized coastal management challenges identified by the survey were: Deteriorating ecosystems leading to reduced (environmental, recreational, economic, storm buffer) functionality, Increasing storminess due to climate change (i.e. more frequent and intense impacts), Coastal flooding, both Sea level rise and associated flooding (e.g. nuisance flooding, king tides), and Combined effects of rainfall and surge on urban flooding (i.e. episodic, short-term), Chronic beach erosion (i.e. high/increasing long-term erosion rates), and Coastal water quality, including harmful algal blooms (e.g. red tide, sargassum). A careful, systematic, and interdisciplinary approach should direct efforts to identify specific research needed to tackle these challenges. A notable shift in priorities from erosion to water-related challenges was recorded from respondents with organizations initially formed for beachfront management. In addition, affiliation-specific and regional responses varied, such as Floridians concern more with harmful algal blooms than any other human and ecosystem health related challenge. The most common need for additional coastal management tools and strategies related to adaptive coastal management to maintain community resilience and continuous storm barriers (dunes, structures), as the top long-term and extreme event needs, respectively. In response to questions about missing information that agencies can provide, respondents frequently mentioned up-to-date data on coastal systems and solutions to challenges as more important than additional tools.

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