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Ploidy Distribution of the Harmful Bloom Forming Macroalgae Ulva spp. in Narragansett Bay, Rhode Island, USA, Using Flow Cytometry Methods
Title
Ploidy Distribution of the Harmful Bloom Forming Macroalgae Ulva spp. in Narragansett Bay, Rhode Island, USA, Using Flow Cytometry Methods.
Creator
Potter, Elaine E., Thornber, Carol S., Swanson, John-David, McFarland, Malcolm, Gobler, Christopher J.
Abstract/Description
Macroalgal blooms occur worldwide and have the potential to cause severe ecological and economic damage. Narragansett Bay, RI is a eutrophic system that experiences summer macroalgal blooms composed mostly of Ulva compressa and Ulva rigida, which have biphasic life cycles with separate haploid and diploid phases. In this study, we used flow cytometry to assess ploidy levels of U. compressa and U. rigida populations from five sites in Narragansett Bay, RI, USA, to assess the relative...
Show moreMacroalgal blooms occur worldwide and have the potential to cause severe ecological and economic damage. Narragansett Bay, RI is a eutrophic system that experiences summer macroalgal blooms composed mostly of Ulva compressa and Ulva rigida, which have biphasic life cycles with separate haploid and diploid phases. In this study, we used flow cytometry to assess ploidy levels of U. compressa and U. rigida populations from five sites in Narragansett Bay, RI, USA, to assess the relative contribution of both phases to bloom formation. Both haploid gametophytes and diploid sporophytes were present for both species. Sites ranged from a relative overabundance of gametophytes to a relative overabundance of sporophytes, compared to the null model prediction of 2 gametophytes: 1 sporophyte. We found significant differences in cell area between ploidy levels for each species, with sporophyte cells significantly larger than gametophyte cells in U. compressa and U. rigida.We found no differences in relative growth rate between ploidy levels for each species. Our results indicate the presence of both phases of each of the two dominant bloom forming species throughout the bloom season, and represent one of the first studies of in situ Ulva life cycle dynamics.
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Date Issued
2016-02-26
PURL
http://purl.flvc.org/fau/fd/FAUIR000037
Format
Citation
MARINE MICROBIAL INTERACTIONS: A TALE OF TWO CITIES
Title
MARINE MICROBIAL INTERACTIONS: A TALE OF TWO CITIES.
Creator
Palau, Jackie Lin, McFarland, Malcolm, Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
Abstract/Description
Microbial partners provide beneficial and detrimental functions to their hosts and other microbes through the exchange of metabolites and info chemicals. Developing an understanding of these micro-interactions has considerable implications for human health, agriculture, and ecosystem protection. Here, the microbial interactions of two important marine organisms: the Forcepia sp. sponge, a source of the potential anticancer compound, lasonolide A (LSA), and Pyrodinium bahamense, a...
Show moreMicrobial partners provide beneficial and detrimental functions to their hosts and other microbes through the exchange of metabolites and info chemicals. Developing an understanding of these micro-interactions has considerable implications for human health, agriculture, and ecosystem protection. Here, the microbial interactions of two important marine organisms: the Forcepia sp. sponge, a source of the potential anticancer compound, lasonolide A (LSA), and Pyrodinium bahamense, a dinoflagellate which produces the potent neurotoxin, saxitoxin, were investigated. Chapter 1 introduces marine microbial interactions, their importance in the function of organisms and ecosystems, and their applications in human health, agriculture and ecosystem production. Chapter 2 describes the identification and capture of the lasonolide biosynthetic pathway from a metagenomic fosmid library. This chapter also describes the assembly of the pathway into an expression vector and attempts to sustainably produce LSA through heterologous expression. Chapter 3 describes the identification and characterization of the bacterial associates of Pyrodinium bahamense, a toxin producing dinoflagellate found in the northern Indian River Lagoon. This chapter also describes potential chemical and molecular interactions occurring between P. bahamense and its associated cultivable bacteria. Chapter 4 describes the investigation into the effects microbial associates have on the physiology of P. bahamense. The completion of this work further describes microbial interactions occurring in marine environments, their influences and functions in the physiology and evolution of marine organisms, and the tools available for their investigation and utilization for human and ecosystem benefit.
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Date Issued
2024
PURL
http://purl.flvc.org/fau/fd/FA00014532
Subject Headings
Marine microbiology, Pyrodinium bahamense, Microbial Interactions, lasonolide A
Format
Document (PDF)
An Assessment of Potential Threats to Human Health from Algae Blooms in the Indian River Lagoon (USA) 2018–2021: Unique Patterns of Cytotoxicity Associated with Toxins
Title
An Assessment of Potential Threats to Human Health from Algae Blooms in the Indian River Lagoon (USA) 2018–2021: Unique Patterns of Cytotoxicity Associated with Toxins.
Creator
Esther Guzman, Tara A. Peterson, Priscilla L. Winder, Kirstie T. Francis, Malcolm McFarland, Jill C. Roberts, Jennifer Sandle, Amy E. Wright
Abstract/Description
The Indian River Lagoon (IRL), a 156-mile-long estuary located on the eastern coast of Florida, experiences phytoplankton bloom events due to increased seasonal temperatures coupled with anthropogenic impacts. This study aimed to gather data on the toxicity to human cells and to identify secondary metabolites found in water samples collected in the IRL. Water samples from 20 sites of the IRL were collected during the wet and dry seasons over a three-year period. A panel of cell lines was used...
Show moreThe Indian River Lagoon (IRL), a 156-mile-long estuary located on the eastern coast of Florida, experiences phytoplankton bloom events due to increased seasonal temperatures coupled with anthropogenic impacts. This study aimed to gather data on the toxicity to human cells and to identify secondary metabolites found in water samples collected in the IRL. Water samples from 20 sites of the IRL were collected during the wet and dry seasons over a three-year period. A panel of cell lines was used to test cytotoxicity. Hemagglutination, hemolysis, and inhibition of protein phosphatase 2A (PP2A) were also measured. Cytotoxic blooms were seen both in the south (Microcystis) and the north (Pyrodinium) of the IRL. Each toxin induced a consistent pattern of cytotoxicity in the panel of human cell lines assayed. During blooms, cytotoxicity due to a single type of toxin is obvious from this pattern. In the absence of blooms, the cytotoxicity seen reflected either a mixture of toxins or it was caused by an unidentified toxin. These observations suggest that other toxins with the potential to be harmful to human health may be present in the IRL. Moreover, the presence of toxins in the IRL is not always associated with blooms of known toxin-producing organisms.
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Date Issued
2023
PURL
http://purl.flvc.org/fau/fd/FAUIR000517
Format
Document (PDF)