Life Sciences Commons^™

Variation In Symbiont Density Is Linked To Changes In Constitutive Immunity In The Facultatively Symbiotic Coral, Astrangia Poculata, Isabella Changsut, Haley R. Womack, Alicia Shickle, Koty H. Sharp, Lauren E. Fuess

Arts & Sciences Faculty Publications

Scleractinian corals are essential ecosystem engineers, forming the basis of coral reef ecosystems. However, these organisms are in decline globally, in part due to rising disease prevalence. Most corals are dependent on symbiotic interactions with single-celled algae from the family Symbiodiniaceae to meet their nutritional needs, however, suppression of host immunity may be essential to this relationship. To explore immunological consequences of algal symbioses in scleractinian corals, we investigated constitutive immune activity in the facultatively symbiotic coral, Astrangia poculata. We compared immune metrics (melanin synthesis, antioxidant production and antibacterial activity) between coral colonies of varying symbiont density. Symbiont density was …

Variation In Coral Thermotolerance Across A Pollution Gradient Erodes As Coral Symbionts Shift To More Heat-Tolerant Genera, Melissa S. Naugle, Thomas A. Oliver, Daniel J. Barshis, Ruth D. Gates, Cheryl A. Logan

Biological Sciences Faculty Publications

Phenotypic plasticity is one mechanism whereby species may cope with stressful environmental changes associated with climate change. Reef building corals present a good model for studying phenotypic plasticity because they have experienced rapid climate-driven declines in recent decades (within a single generation of many corals), often with differential survival among individuals during heat stress. Underlying differences in thermotolerance may be driven by differences in baseline levels of environmental stress, including pollution stress. To examine this possibility, acute heat stress experiments were conducted on Acropora hyacinthus from 10 sites around Tutuila, American Samoa with differing nutrient pollution impact. A threshold-based heat …

A Comparative Genomics Exploration Of Inter-Partner Metabolic Signaling In The Coral-Algal Symbiosis, Katherine E. Dougan

FIU Electronic Theses and Dissertations

At the foundation of coral reef ecosystems is the symbiosis between the coral host and its microbial community, particularly its photoautotrophic algae from the family Symbiodiniaceae. As a symbiosis centered around nutritional exchange, determining the mechanisms involved in the maintenance of this cooperative exchange is central to understanding how it breaks down. As the nutritional transfer primarily consists of sugars, this work first focuses on the cnidarian insulin signaling pathway, an evolutionarily important metazoan pathway involved in diverse functions, most notably metabolism. This dissertation unveiled 360 putative cnidarian insulin-like peptides (cnILPs) from existing transcriptomic datasets, where they were previously missed …

Uncovering The Role Of Symbiodiniaceae Assemblage Composition And Abundance In Coral Bleaching Response By Minimizing Sampling And Evolutionary Biases, Timothy D. Swain, Simon Lax, Vadim Backman, Luisa A. Marcelino

Marine & Environmental Sciences Faculty Articles

Background

Biodiversity and productivity of coral-reef ecosystems depend upon reef-building corals and their associations with endosymbiotic Symbiodiniaceae, which offer diverse functional capabilities to their hosts. The number of unique symbiotic partners (richness) and relative abundances (evenness) have been hypothesized to affect host response to climate change induced thermal stress. Symbiodiniaceae assemblages with many unique phylotypes may provide greater physiological flexibility or form less stable symbioses; assemblages with low abundance phylotypes may allow corals to retain thermotolerant symbionts or represent associations with less-suitable symbionts.

Results

Here we demonstrate that true richness of Symbiodiniaceae phylotype assemblages is generally not discoverable from …

Characterization Of The Microbiome And Bioluminescent Symbionts Across Life Stages Of Ceratioid Anglerfishes Of The Gulf Of Mexico, Lindsay L. Freed, Cole Easson, Lydia Baker, D. Fenolio, Tracey Sutton, Yasmin Khan, Patricia Blackwelder, Tory Hendry, Jose Lopez

Biology Faculty Articles

The interdependence of diverse organisms through symbiosis reaches even the deepest parts of the oceans. As part of the DEEPEND project (deependconsortium.org) research on deep Gulf of Mexico biodiversity, we profiled the bacterial communities (‘microbiomes’) and luminous symbionts of 36 specimens of adult and larval deep-sea anglerfishes of the suborder Ceratioidei using 16S rDNA. Transmission Electron Microscopy was used to characterize the location of symbionts in adult light organs (esca). Whole larval microbiomes, and adult skin and gut microbiomes, were dominated by bacteria in the genera Moritella and Pseudoalteromonas genera. 16S rDNA sequencing results from adult fishes corroborate …

Evolutionary Expansions And Neofunctionalization Of Ionotropic Glutamate Receptors In Cnidaria, Ellen G. Dow

FIU Electronic Theses and Dissertations

Reef ecosystems are composed of a variety of organisms, transient species of fish and invertebrates, microscopic bacteria and viruses, and structural organisms that build the living foundation, coral. Sessile cnidarians, corals and anemones, interpret dynamic environments of organisms and abiotic factors through a molecular interface. Recognition of foreign molecules occurs through innate immunity via receptors identifying conserved molecular patterns. Similarly, chemosensory receptors monitor the environment through specific ligands. Chemosensory receptors include ionotropic glutamate receptors (iGluRs), transmembrane ion channels involved in chemical sensing and neural signal transduction. Recently, an iGluR homolog was implicated in cnidarian immunological resistance to recurrent infections of …

Florida's Pillar Coral (Dendrogyra Cylindrus): The Roles Of The Holobiont Partners In Bleaching, Recovery, And Disease Processes, Cynthia Fairbank Lewis

FIU Electronic Theses and Dissertations

The iconic pillar coral, Dendrogyra cylindrus, is one of five Caribbean species listed in 2014 under the US Federal Endangered Species Act because of its extreme low abundance and continued decline in US waters. Until recently, little was known about the demographics or genetic diversity of Florida’s D. cylindrus population. This study represents the first time two holobiont partners (coral animal and associated photosynthetic algal endosymbionts) have been closely examined, spatially and temporally, in this little-studied species. The aim was to explore the influences of coral animal genotypes, mutualistic photosynthetic algal strains, and hyperthermal stress on bleaching and …

Ongoing Transposon-Mediated Genome Reduction In The Luminous Bacterial Symbionts Of Deep-Sea Ceratioid Anglerfishes, Tory Hendry, Lindsay L. Freed, Dana Fadera, Dante Fenolio, Tracey Sutton, Jose Lopez

Marine & Environmental Sciences Faculty Articles

Diverse marine fish and squid form symbiotic associations with extracellular bioluminescent bacteria. These symbionts are typically free-living bacteria with large genomes, but one known lineage of symbionts has undergone genomic reduction and evolution of host dependence. It is not known why distinct evolutionary trajectories have occurred among different luminous symbionts, and not all known lineages previously had genome sequences available. In order to better understand patterns of evolution across diverse bioluminescent symbionts, we de novo sequenced the genomes of bacteria from a poorly studied interaction, the extracellular symbionts from the “lures” of deep-sea ceratioid anglerfishes. Deep-sea anglerfish symbiont genomes are …

The Sponge Microbiome Project, Lucas Moitinho-Silva, Shaun Nielsen, Amnon Amir, Antonio Gonzalez, Gail Ackermann, Carlo Cerrano, Carmen Astudillo-Garcia, Cole Easson, Detmer Sipkema, Fang Liu, Georg Steinert, Giorgos Kotoulas, Grace Mccormack, Guofang Feng, James J. Bell, Jan Vicente, Johannes R. Bjork, Jose M. Montoya, Julie B. Olson, Julie Reveillaud, Laura Steindler, Mari-Carmen Pineda, Maria V. Marra, Micha Ilan, Michael W. Taylor, Paraskevi Polymenakou, Patrick M. Erwin, Peter J. Schupp, Rachel L. Simister, Rob Knight, Robert W. Thacker, Rodrigo Costa, Russell T. Hill, Susanna Lopez-Legentil, Thanos Dailianis, Timothy Ravasi, Ute Hentschel, Zhiyong Li, Nicole S. Webster, Torsten Thomas

Marine & Environmental Sciences Faculty Articles

Marine sponges (phylum Porifera) are a diverse, phylogenetically deep-branching clade known for forming intimate partnerships with complex communities of microorganisms. To date, 16S rRNA gene sequencing studies have largely utilised different extraction and amplification methodologies to target the microbial communities of a limited number of sponge species, severely limiting comparative analyses of sponge microbial diversity and structure. Here, we provide an extensive and standardised dataset that will facilitate sponge microbiome comparisons across large spatial, temporal, and environmental scales. Samples from marine sponges (n = 3569 specimens), seawater (n = 370), marine sediments (n = 65) and other …

The Individual And Interactive Effects Of Nitrogen And Phosphorus Enrichment On Coral Reefs, Andrew A. Shantz

FIU Electronic Theses and Dissertations

Human domination of global nutrient cycles is profoundly altering our planet. Yet on coral reefs, the effects of changing nutrient regimes have likely been over-simplified. This dissertation investigates the complexity of animal-nutrient interactions at the organismal level and explores how the outcomes of these interactions cascade through levels of biological organization. To do so, I examined the effects of nitrogen (N) and phosphorus (P) on corals and macroalgae, and how these effects in turn influenced reef communities and entire ecosystems. I show that P consistently increases coral growth rates while N has variable, often negative, effects on coral growth. The …

Skeletal Light-Scattering Accelerates Bleaching Response In Reef-Building Corals, Timothy D. Swain, Emily Dubois, Andrew Gomes, Valentina P. Stoyneva, Andrew J. Radosevich, Jillian Henss, Michelle E. Wagner, Justin Derbas, Hannah Grooms, Elizabeth M. Velazquez, Joshua Traub, Brian J. Kennedy, Arabela A. Grigorescu, Mark W. Westneat, Kevin Sanborn, Shoshana Levine, Mark Schick, George Parsons, Brendan C. Briggs, Jeremy D. Rogers, Vadim Backman, Luisa A. Marcelino

Marine & Environmental Sciences Faculty Articles

Background At the forefront of ecosystems adversely affected by climate change, coral reefs are sensitive to anomalously high temperatures which disassociate (bleaching) photosynthetic symbionts (Symbiodinium) from coral hosts and cause increasingly frequent and severe mass mortality events. Susceptibility to bleaching and mortality is variable among corals, and is determined by unknown proportions of environmental history and the synergy of Symbiodinium- and coral-specific properties. Symbiodinium live within host tissues overlaying the coral skeleton, which increases light availability through multiple light-scattering, forming one of the most efficient biological collectors of solar radiation. Light-transport in the upper ~200 μm layer …

Sponge Distribution And The Presence Of Photosymbionts In Moorea, French Polynesia, Christopher J. Freeman, Cole Easson

Marine & Environmental Sciences Faculty Articles

Photosymbionts play an important role in the ecology and evolution of diverse host species within the marine environment. Although sponge-photosymbiont interactions have been well described from geographically disparate sites worldwide, our understanding of these interactions from shallow water systems within French Polynesia is limited. We surveyed diverse habitats around the north coast of Moorea, French Polynesia and screened sponges for the presence of photosymbionts. Overall sponge abundance and diversity were low, with <1% cover and only eight putative species identified by 28S barcoding from surveys at 21 sites. Of these eight species, seven were found predominately in shaded or semi-cryptic habitats under overhangs or within caverns. Lendenfeldia chondrodeswas the only species that supported a high abundance of photosymbionts and was also the only species found in exposed, illuminated habitats. Interestingly, L. chondrodes was …

Symbiont Presence And Identity Influence Life History Strategies Of A Temperate Sea Anemone, Brian L. Bingham, James L. Dimond, Gisele Muller-Parker

Environmental Sciences Faculty and Staff Publications

Along the North American Pacific coast, the common intertidal sea anemone Anthopleura elegantissima engages in facultative, flexible symbioses with Symbiodinium muscatinei (a dinoflagellate) and Elliptochloris marina (a chloro- phyte). Determining how symbiotic state affects host fitness is essential to understanding the ecological significance of engaging in such flexible relationships with diverse symbionts. Fitness consequences of hosting S. muscatinei, E. marina or negligible numbers of either symbiont (aposymbiosis) were investigated by measuring growth, cloning by fission and gonad development after 8.5 – 11 months of sustained exposure to high, moderate or low irradiance under seasonal environmental conditions. Both symbiotic state …

Acclimatization Of The Tropical Reef Coral Acropora Millepora To Hyperthermal Stress, Anthony John Bellantuono

FIU Electronic Theses and Dissertations

The demise of reef-building corals potentially lies on the horizon, given ongoing climate change amid other anthropogenic environmental stressors. If corals cannot acclimatize or adapt to changing conditions, dramatic declines in the extent and health of the living reefs are expected within the next half century. The primary and proximal global threat to corals is climate change. Reef-building corals are dependent upon a nutritional symbiosis with photosynthetic dinoflagellates belonging to the group Symbiodinium. The symbiosis between the cnidarian host and algal partner is a stress-sensitive relationship; temperatures just 1°C above normal thermal maxima can result in the breakdown of …

Eager: Collaborative Research: Developing Transformation Technologies For Porphyra, Susan H. Brawley

University of Maine Office of Research Administration: Grant Reports

The genome of the marine red alga Porphyra umbilicalis is being sequenced by the Joint Genome Institute. The sequence information will help scientists address many fundamental questions, because Porphyra spp. belong to an ancient eukaryotic lineage, are important human foods ("nori"), have complex life histories, and---even compared to other intertidal organisms--- possess an unusually stress-tolerant metabolism. Computer-based analyses of the new genomic data will be sufficient to address some research questions, but most studies (e.g., the basis of Porphyra's tolerance to extreme drying or high light) will require experimental approaches based upon bioinformatics analyses. This project will develop the essential …

Testing The Role Of Male-Male Competition In The Evolution Of Sexual Dimorphism: A Comparison Between Two Species Of Porcelain Crabs, J. Antonio Baeza, Cynthia M. Asorey

Biological Sciences Faculty Publications

Theory predicts marked sexual dimorphism in terms of body size and body structures used as weapons (e.g. chelipeds) in gonochoric species with intense male sexual competition for receptive females and reduced or no sexual dimorphism in species where competition among males is trivial. We tested this hypothesis using a pair of closely-related species of symbiotic porcelain crabs as a model. In one species that inhabits sea anemones solitarily, competition among males for receptive females is unimportant. In a second species that dwells as dense aggregations on sea urchins, malemale competition for sexual partners is recurrent. We expected considerable sexual dimorphism …