Life Sciences Commons^™

Space-For-Time Substitution Works In Everglades Ecological Forecasting Models, Amanda I. Banet, Joel C. Trexler

Department of Biological Sciences

Space-for-time substitution is often used in predictive models because long-term time-series data are not available. Critics of this method suggest factors other than the target driver may affect ecosystem response and could vary spatially, producing misleading results. Monitoring data from the Florida Everglades were used to test whether spatial data can be substituted for temporal data in forecasting models. Spatial models that predicted bluefin killifish (Lucania goodei) population response to a drying event performed comparably and sometimes better than temporal models. Models worked best when results were not extrapolated beyond the range of variation encompassed by the original …

Bivalve Omics: State Of The Art And Potential Applications For The Biomonitoring Of Harmful Marine Compounds, Victoria Suárez-Ulloa, Juan Fernández-Tajes, Chiara Manfrin, Marco Gerdol, Paola Venier, José M. Eirín-López

Department of Biological Sciences

The extraordinary progress experienced by sequencing technologies and bioinformatics has made the development of omic studies virtually ubiquitous in all fields of life sciences nowadays. However, scientific attention has been quite unevenly distributed throughout the different branches of the tree of life, leaving molluscs, one of the most diverse animal groups, relatively unexplored and without representation within the narrow collection of well established model organisms. Within this Phylum, bivalve molluscs play a fundamental role in the functioning of the marine ecosystem, constitute very valuable commercial resources in aquaculture, and have been widely used as sentinel organisms in the biomonitoring of …

Deep Sequencing Analyses Expands The Pseudomonas Aeruginosa Ampr Regulon To Include Small Rna-Mediated Regulation Of Iron Acquisition, Heat Shock And Oxidative Stress Response, Deepak Balasubramania, Hansi Kumari, Melita Jaric, Mitch Fernandez, Keith H. Turner, Simon L. Dove, Giri Narasimhan, Stephen Lory, Kalai Mathee

Department of Biological Sciences

Pathogenicity of Pseudomonas aeruginosa, a major cause of many acute and chronic human infections, is determined by tightly regulated expression of multiple virulence factors. Quorum sensing (QS) controls expression of many of these pathogenic determinants. Previous microarray studies have shown that the AmpC β-lactamase regulator AmpR, a member of the LysR family of transcription factors, also controls non-β-lactam resistance and multiple virulence mechanisms. Using RNA-Seq and complementary assays, this study further expands the AmpR regulon to include diverse processes such as oxidative stress, heat shock and iron uptake. Importantly, AmpR affects many of these phenotypes, in part, by regulating expression …

Okadaic Acid Meet And Greet: An Insight Into Detection Methods, Response Strategies And Genotoxic Effects In Marine Invertebrates, María Verónica Prego-Faraldo, Vanessa Valdiglesias, Josefina Méndez, Jose M. Eirin-Lopez

Department of Biological Sciences

Harmful Algal Blooms (HABs) constitute one of the most important sources of contamination in the oceans, producing high concentrations of potentially harmful biotoxins that are accumulated across the food chains. One such biotoxin, Okadaic Acid (OA), is produced by marine dinoflagellates and subsequently accumulated within the tissues of filtering marine organisms feeding on HABs, rapidly spreading to their predators in the food chain and eventually reaching human consumers causing Diarrhetic Shellfish Poisoning (DSP) syndrome. While numerous studies have thoroughly evaluated the effects of OA in mammals, the attention drawn to marine organisms in this regard has been scarce, even though …

Farnesyl Phosphatase, A Corpora Allata Enzyme Involved In Juvenile Hormone Biosynthesis In Aedes Aegypti, Pratik Nyati, Marcela Nouzova, Crisalejandra Rivera-Perez, Mark E. Clifton, Jamie G. Mayoral, Fernando G. Noriega

Department of Biological Sciences

Background: The juvenile hormones (JHs) are sesquiterpenoid compounds that play a central role in insect reproduction, development and behavior. The late steps of JH III biosynthesis in the mosquito Aedes aegypti involve the hydrolysis of farnesyl pyrophosphate (FPP) to farnesol (FOL), which is then successively oxidized to farnesal and farnesoic acid, methylated to form methyl farnesoate and finally transformed to JH III by a P450 epoxidase. The only recognized FPP phosphatase (FPPase) expressed in the corpora allata (CA) of an insect was recently described in Drosophila melanogaster (DmFPPase). In the present study we sought to molecularly and biochemically characterize the …

Native Predators Do Not Influence Invasion Success Of Pacific Lionfish On Caribbean Reefs, Serena Hackerott, Abel Valdivia, Stephanie J. Green, Isabelle M. Cote, Courtney E. Cox, Lad Akins, Craig A. Layman, William F. Precht, John F. Bruno

Department of Biological Sciences

Biotic resistance, the process by which new colonists are excluded from a community by predation from and/or competition with resident species, can prevent or limit species invasions. We examined whether biotic resistance by native predators on Caribbean coral reefs has influenced the invasion success of red lionfishes (Pterois volitans and Pterois miles), piscivores from the Indo-Pacific. Specifically, we surveyed the abundance (density and biomass) of lionfish and native predatory fishes that could interact with lionfish (either through predation or competition) on 71 reefs in three biogeographic regions of the Caribbean. We recorded protection status of the reefs, and abiotic variables …

Transcriptional Activation Of C3 And Hsp70 As Part Of The Immune Response Of Acropora Millepora To Bacterial Challenges, Tanya Brown, David Bourne, Mauricio Rodriguez-Lanetty

Department of Biological Sciences

The impact of disease outbreaks on coral physiology represents an increasing concern for the fitness and resilience of reef ecosystems. Predicting the tolerance of corals to disease relies on an understanding of the coral immune response to pathogenic interactions. This study explored the transcriptional response of two putative immune genes (c3 and c-type lectin) and one stress response gene (hsp70) in the reef building coral, Acropora millepora challenged for 48 hours with bacterial strains, Vibrio coralliilyticus and Alteromonas sp. at concentrations of 106 cells ml-1. Coral fragments challenged with V. coralliilyticus appeared healthy while fragments challenged with Alteromonas sp. showed …

Flying Fruit Flies Correct For Visual Sideslip Depending On Relative Speed Of Forward Optic Flow, Stephanie Cabrera, Jamie Theobald

Department of Biological Sciences

As a fly flies through its environment, static objects produce moving images on its retina, and this optic flow is essential for steering and course corrections. Different types of rotation and translation produce unique flow fields, which fly brains are wired to identify. However, a feature of optic flow unique to translational motion is that adjacent images may move across the retina at different speeds, depending on their distance from the observer. Many insects take advantage of this depth cue, called motion parallax, to determine the distance to objects. We wanted to know if differential object speeds affect the corrective …

Flying Fruit Flies Correct For Visual Sideslip Depending On Relative Speed Of Forward Optic Flow, Stephanie Cabrera, Jamie Theobald

Department of Biological Sciences

As a fly flies through its environment, static objects produce moving images on its retina, and this optic flow is essential for steering and course corrections. Different types of rotation and translation produce unique flow fields, which fly brains are wired to identify. However, a feature of optic flow unique to translational motion is that adjacent images may move across the retina at different speeds, depending on their distance from the observer. Many insects take advantage of this depth cue, called motion parallax, to determine the distance to objects. We wanted to know if differential object speeds affect the corrective …

A Comprehensive And Integrative Reconstruction Of Evolutionary History For Anomura (Crustacea: Decapoda), Heather D. Bracken-Grissom, Maren E. Cannon, Patricia Cabezas, Rodney M. Feldmann, Carrie E. Schweitzer, Shane T. Ahyong, Darryl L. Felder, Rafael Lemaitre

Department of Biological Sciences

Background

The infraorder Anomura has long captivated the attention of evolutionary biologists due to its impressive morphological diversity and ecological adaptations. To date, 2500 extant species have been described but phylogenetic relationships at high taxonomic levels remain unresolved. Here, we reconstruct the evolutionary history—phylogeny, divergence times, character evolution and diversification—of this speciose clade. For this purpose, we sequenced two mitochondrial (16S and 12S) and three nuclear (H3, 18S and 28S) markers for 19 of the 20 extant families, using traditional Sanger and next-generation 454 sequencing methods. Molecular data were combined with 156 morphological characters in order to estimate the largest …

Microhabitat Selection By Marine Mesoconsumers In A Thermally Heterogeneous Habitat: Behavioral Thermoregulation Or Avoiding Predation Risk?, Jeremy J. Vaudo, Michael R. Heithaus

Department of Biological Sciences

Habitat selection decisions by consumers has the potential to shape ecosystems. Understanding the factors that influence habitat selection is therefore critical to understanding ecosystem function. This is especially true of mesoconsumers because they provide the link between upper and lower tropic levels. We examined the factors influencing microhabitat selection of marine mesoconsumers – juvenile giant shovelnose rays (Glaucostegus typus), reticulate whiprays (Himantura uarnak), and pink whiprays (H. fai) – in a coastal ecosystem with intact predator and prey populations and marked spatial and temporal thermal heterogeneity. Using a combination of belt transects and data …

Nutrient Supply From Fishes Facilitates Macroalgae And Suppresses Corals In A Caribbean Coral Reef Ecosystem, Deron E. Burkepile, Jacob E. Allgeier, Andrew A. Shantz, Catherine Pritchard, Nathan P. Lemoine, Laura H. Bhatti, Craig A. Layman

Department of Biological Sciences

On coral reefs, fishes can facilitate coral growth via nutrient excretion; however, as coral abundance declines, these nutrients may help facilitate increases in macroalgae. By combining surveys of reef communities with bioenergetics modeling, we showed that fish excretion supplied 25 times more nitrogen to forereefs in the Florida Keys, USA, than all other biotic and abiotic sources combined. One apparent result was a positive relationship between fish excretion and macroalgal cover on these reefs. Herbivore biomass also showed a negative relationship with macroalgal cover, suggesting strong interactions of top-down and bottom-up forcing. Nutrient supply by fishes also showed a negative …

Could Relatedness Help Explain Why Individuals Lead In Bottlenose Dolphin Groups?, Jennifer S. Lewis, Douglas Wartzok, Michael R. Heithaus, Michael Krützen

Department of Biological Sciences

In many species, particular individuals consistently lead group travel. While benefits to followers often are relatively obvious, including access to resources, benefits to leaders are often less obvious. This is especially true for species that feed on patchy mobile resources where all group members may locate prey simultaneously and food intake likely decreases with increasing group size. Leaders in highly complex habitats, however, could provide access to foraging resources for less informed relatives, thereby gaining indirect benefits by helping kin. Recently, leadership has been documented in a population of bottlenose dolphins (Tursiops truncatus) where direct benefits to leaders …

The Chromevaloa Database: A Resource For The Evaluation Of Okadaic Acid Contamination In The Marine Environment Based On The Chromatin-Associated Transcriptome Of The Mussel Mytilus Galloprovincialis, Victoria Suárez-Ulloa, Juan Fernández-Tajes, Vanessa Aguiar-Pulido, Ciro Rivera-Casas, Rodrigo González-Romero, Juan Ausio, Josefina Méndez, Julián Dorado, Jose M. Eirin-Lopez

Department of Biological Sciences

Okadaic Acid (OA) constitutes the main active principle in Diarrhetic Shellfish Poisoning (DSP) toxins produced during Harmful Algal Blooms (HABs), representing a serious threat for human consumers of edible shellfish. Furthermore, OA conveys critical deleterious effects for marine organisms due to its genotoxic potential. Many efforts have been dedicated to OA biomonitoring during the last three decades. However, it is only now with the current availability of detailed molecular information on DNA organization and the mechanisms involved in the maintenance of genome integrity, that a new arena starts opening up for the study of OA contamination. In the present work …

Disturbance Driven Colony Fragmentation As A Driver Of A Coral Disease Outbreak, Marilyn E. Brandt, Tyler B. Smith, Adrienne M.S. Correa, Rebecca Vega-Thurber

Department of Biological Sciences

In September of 2010, Brewer's Bay reef, located in St. Thomas (U.S. Virgin Islands), was simultaneously affected by abnormally high temperatures and the passage of a hurricane that resulted in the mass bleaching and fragmentation of its coral community. An outbreak of a rapid tissue loss disease among coral colonies was associated with these two disturbances. Gross lesion signs and lesion progression rates indicated that the disease was most similar to the Caribbean coral disease white plague type 1. Experiments indicated that the disease was transmissible through direct contact between colonies, and five-meter radial transects showed a clustered spatial distribution …

Diurnal Patterns Of Gas-Exchange And Metabolic Pools In Tundra Plants During Three Phases Of The Arctic Growing Season, Rajit Patankar, Behzad Mortazavi, Steven F. Oberbauer, Gregory Starr

Department of Biological Sciences

Arctic tundra plant communities are subject to a short growing season that is the primary period in which carbon is sequestered for growth and survival. This period is often characterized by 24-h photoperiods for several months a year. To compensate for the short growing season tundra plants may extend their carbon uptake capacity on a diurnal basis, but whether this is true remains unknown. Here, we examined in situ diurnal patterns of physiological activity and foliar metabolites during the early, mid, and late growing season in seven arctic species under light-saturated conditions. We found clear diurnal patterns in photosynthesis and …