REU program mentors, summer 2017
Dr. John Bowden: Environmental Omics
Dr. Marie DeLorenzo: Environmental Toxicology
Dr. Tony Harold: Fish Ecology and Diversity
Dr. Peter Lee: Phytoplankton Ecology and Microbial Oceanography
Dr. Craig Plante: Marine Microbial Ecology
Dr. Bob Podolsky: Environmental Stress on Early Life-History Stages
Dr. Erik Sotka: Marine Invasions and Stress Tolerance
Dr. Demitri Spyropolous: Impacts of Environmental Endocrine Disruptors
Dr. Allison Welch: Habitat Salinization and Amphibian Biology
Dr. Cheryl Woodley: Biochemistry, Molecular and Cell Biology of Corals
Mentor lab descriptions
Following are general descriptions of the work done in labs of mentors for this year’s program. Specific intern projects will be worked out after selection and closer to the time of the program. Institutional and building abbreviations listed for each mentor are explained at the bottom of this page.
Dr. John Bowden (NIST/HML, john.bowden (at) noaa.gov)
Lipids present a unique target of disease state biomarkers, mainly due to the fact that they are ubiquitous and exhibit a variety of physiological roles. Lipidomics, or an examination of the lipidome using mass spectrometry, has been successfully applied for the discovery and increased understanding of human diet/nutrition, health, development, and disease etiology. Parallel to humans, several wildlife species have exhibited an increase in the occurrence of pathophysiological conditions, including cancers, altered metabolism, decreased fertility, inflammation, and impaired development. The work in our lab focuses on pursuing and adapting omics-based approaches commonly employed in human disease research, such as lipidomics and metabolomics, to assess environmental health, an arena in which these approaches have rarely been adapted. Efforts have been placed to develop and tailor analytical strategies (chromatography, mass spectrometry, data informatics) for the detection of novel disease state biomarkers and to apply the developed strategies to on-going environmental studies. The student would get “hands on” experience in an analytical and environmental chemistry laboratory, using state of the art instrumentation and measurement practices, as well as work with unique aquatic wildlife species (e.g., marine mammals, coral, fish, alligators, etc.).
Dr. Marie DeLorenzo (NOAA/CCEBHR, marie.delorenzo (at) noaa.gov)
Bioeffects of chemical contaminants and other environmental stressors
Possible project: Effects of ultraviolet (UV) light on toxicity of surface oil slicks in early life stages of marine organisms
Background: One of the lingering questions after the Deepwater Horizon oil spill is the toxicity of thin oil sheens to early life stages of aquatic species, and whether that toxicity may be magnified by interaction of hydrocarbon compounds with UV light. Previous studies have shown several polycyclic aromatic hydrocarbons (PAHs) become more toxic in the presence of natural sunlight. UV-induced PAH toxicity occurs in a wide variety of organisms, and larval life-stages may be among the most sensitive.
Approach: The project this summer will be assessing the impact of UV light on toxicity of thin oil sheens to early life stages of marine species. We will be comparing oils sheen toxicity with and without UV-light exposure. We will determine acute mortality thresholds, as well as sublethal responses such as embryo hatching success and timing, larval development, and growth. Cellular biomarkers, such as lipid peroxidase activity and cytochrome p450, will also be included.
Student interns headed to collect field samples
Dr. Tony Harold (CofC/GML, harolda (at) cofc.edu)
Fish ecology and diversity
We have been working in several areas, including evolutionary relationships, biodiversity discovery, and ecology of inshore fishes. Small benthic fishes such as gobies and blennies are very abundant and are likely to represent important trophic components of estuarine communities. However, little is known about their patterns of colonization with respect to the various benthic habitat types, such as oyster shell, indigenous and invasive algae, and various types of unconsolidated substrate. We will use various techniques to capture larval, postlarval and juvenile fishes, which will then be preserved, identified, staged, and measured. The relative importance of the various habitat types will be determined through use of several types of statistical analysis. The findings of this work will have a bearing on our understanding of the dynamics of estuarine food webs and management of habitats critical to the support of prey species.
Students sampling the surf zone for juvenile fishes
Dr. Peter Lee (CofC/HML, leep (at) cofc.edu)
Phytoplankton Ecology and Microbial Oceanography
Research projects underway in my lab that could involve REU student participation include:
1. Effect of Vitamin B12 on phytoplankton growth and metabolite production:
New evidence is revealing that Vitamin B12 may be a critical trace nutrient in marine ecosystems. B12 is only produced by certain bacteria and archaea. Consequently, all eukaryotic organisms and those prokaryotes that cannot produce their own B12 must take it up from their environment. Ongoing research in the lab is exploring how B12 availability impacts phytoplankton growth and the production of the methionine. In addition to its importance as an amino acid, methionine is also the precursor to the algal osmolyte dimethylsulphoniopropionate, which has been linked to the formation of clouds.
Lee PA, et al. 2015.Influence of vitamin B12 availability on oceanic dimethylsulfide and dimethylsulfoniopropionate. Environmental Chemistry doi: 10.1071/EN15043
2. Energy use and organic carbon production by microbes in subglacial lakes:
Recent advances in various technologies and scientific techniques have allowed scientists to explore and sample subglacial environments for the first time. Some of these bodies of water are remnants of coastal seas that were trapped by advancing polar ice caps whilst others are freshwater lakes. We are exploring how the microbial communities in these environments have changed as a result of prolonged isolation from the atmosphere and sunlight for photosynthesis. Key questions include what substrates do the organisms use as energy sources and what organic compounds do they produce that might be used by other organisms for growth?
Mikucki JA, et al. 2016. Subglacial Lake Whillans Microbial Biogeochemistry: A synthesis of current knowledge. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 374: 20140290. doi: 10.1098/rsta.2014.0290
REU intern Bryce Penta measuring phytoplankton
Dr. Craig Plante (CofC/GML, plante (at) cofc.edu)
Marine microbial ecology
The research focus of the Plante lab is marine microbial ecology. Current projects include study of the biogeography and community assembly of benthic microalgae, disturbance and resilience of microalgae to beach renourishments, and sea turtle nest microbiology.
Methodologies commonly employed include field sampling and/or experimentation (on beaches, sand- or mud-flats), microbial culture techniques, molecular biological methods for microbial community analysis, and the bioinformatics pipeline Qiime. Typically the lab consists of the Dr. Plante, one graduate student, 2-3 undergraduate student researchers, and a part-time technician.
REU intern Jessie Lowry working on microbial community structure
Dr. Bob Podolsky (CofC/GML, podolskyr (at) cofc.edu)
Environmental biology and ecology of early life stages of marine invertebrates
My laboratory asks questions about the effects of environmental conditions and stressors on early life-history stages (gametes, embryos and larvae) of marine invertebrates. Invertebrates show enormous diversity in larval form and development mode, and their larvae play critical roles in marine food webs and the coupling of benthic and pelagic habitats. In order to assess risks of future climate change, it is critical to understand which life-history stages are most sensitive to environmental stressors. We typically use echinoderm (sea urchin or sand dollar) gametes and larvae or mollusc (snail or nudibranch) embryos to address questions about free-swimming or encapsulated development, respectively. Recent REU projects in my lab have focused on the effects of ocean acidification, global warming, and environmental pollutants on fertilization success, larval growth and development, larval physiology, and encapsulated embryonic growth and shell formation. This summer’s effort will follow-up on the findings of one of these recent projects.
REU intern Emily Hall rearing sea urchin larvae in the laboratory
Dr. Erik Sotka (CofC/GML, sotkae (at) cofc.edu)
Adaptive potential of stress tolerance traits in a marine invasive species
Microevolution of introduced species likely facilitates invasion success, but we have less empirical support for its importance than for demographic and ecological processes. This gap is particularly acute for introduced marine species, which are accelerating in number and impacts but whose microevolution is rarely documented. This project focuses on genetic adaptation of stress tolerance during and after the invasion of the red seaweed Gracilaria vermiculophylla within North American shorelines from its native Japan. Previous work indicated that introduced thalli have greater tolerance for extreme heat, cold and low-salinity stresses. These differences likely reflect rapid evolutionary shifts during the last 100 years. We also detected a latitudinal decline in heat tolerance along eastern North American shores that recapitulated a parallel decline in native Japan. This novel cline indicates that the spread of G. vermiculophylla along an introduced shoreline was sometimes accompanied by local adaptation after establishment. However, these studies only focused on population-level patterns. Future evolutionary change of a single population will depend on levels of between-clone variation in stress tolerance, and how variation in heat, cold and salinity stress might covary among traits. An REU student will use well-established techniques to answer three questions: are there differences in tolerance for heat, cold and salinity stress among clones on a single shoreline? Do these differences have a genetic basis? Are there tradeoffs in tolerating alternative stresses? The REU student will collect and rear several dozens of clonal seaweed individuals, measure their stress tolerances, and assess correlations in these clonal traits.
REU intern Connon Thomas presenting his work on invasive seaweeds
Dr. Demitri Spyropolous (MUSC/HML, spyropdd (at) musc.edu)
Impacts of Environmental Endocrine Disruptors
My laboratory performs gene-by-environment research that links embryonic origins to adult diseases. We study homeobox, PPARγ/RXRα and Ets master regulators, which control cell ‘fate decisions’ and, in turn are controlled by natural and anthropogenic endocrine disrupting compounds (EDCs). Massive increases in EDCs closely parallel multiple emerging marine and human health issues. For this work, we rely on cell-based systems and sentinel models to identify EDCs and predict health trajectories. Our sentinel models range from sophisticated transgenic rodent models to marine mammal/vertebrate (whale, alligator, terrapin) models. With these models we observe that common estrogenic-antiandrogenic contaminants profoundly alter embryonic master regulator patterns, obesity, reproduction and cancer. Sex determination in alligator and terrapin models adds a level of sensitivity to EDC detection and impacts. Further, we observe that genetic background and/or exposure history can profoundly change phenotype. To develop sentinel-/patient-specific models, we developed a method for maintaining viability after freezing of freshly excised human tissues from surgery and biopsies from marine mammal strandings (live cell and intact 3D architecture exposure models). Induced pluripotent stem cells (iPSCs) also serve as surrogates for studying the impact of EDCs on embryonic fate. Most recently, we used human iPSCs to show that a major component of COREXIT, the Gulf Oil Spill dispersant, is a potent ‘obesogen’ that drives stem cell to fat cell fate at the expense of bone formation. Nearly 2 million gallons of COREXIT were used for Deep Water Horizon oil spill clean-up and the obesogenic component is also widely by women during pregnancy. This underscores our need as “tool builders” to better appreciate the influences of our tools on complex organismal and ecological systems. In our work, we hope provide methods to test novel dispersants; methods that go beyond organism/cell toxicity testing to more fully understand their potential to perturb long-term health trajectories.
REU intern Melissa Rex studying the effects of endocrine disruptors
Dr. Allison Welch (CofC/GML, welcha (at) cofc.edu)
Habitat salinization and amphibian conservation biology
My lab is interested in the ecology, behavior and conservation of amphibians. Amphibians are among the most imperiled groups on Earth, with nearly one-third of all species considered threatened or endangered. These ecologically important organisms face complex and interacting threats from pollution, emerging infectious diseases, habitat modification and loss, and climate change. To better understand the vulnerabilities of amphibian populations, we are investigating effects of various anthropogenic environmental stressors – including elevated salinity, pharmaceutical pollutants, and pesticides – across different stages of the amphibian life cycle. Habitat salinization is an emerging threat for freshwater organisms, particularly in coastal regions where rising sea levels, storm surges, and changes in water use can lead to elevated salinity of freshwater habitats. Amphibians, which typically rely on freshwater environments for reproduction and larval development, are particularly vulnerable to habitat salinization. The REU student will be involved in studies examining effects of elevated salinity on sperm function, fertilization, and other important amphibian life stages. This work will combine field work and laboratory experiments with local amphibian populations.
REU intern Annika Wilder checking salinization experiment
Dr. Cheryl Woodley (NOAA/HML, cheryl.woodley (at) noaa.gov)
Molecular genetics, cell physiology and biochemistry of corals
Research in my lab focuses on the application of biochemistry, molecular and cellular biology and pathology to understanding the effects of biotic and abiotic stressors on coral health. Our lab has addressed assay development for various bioindicators (e.g., porphyrins, DNA damage, immune status), coral ESTs and coral-associated microbial community analyses. We are using these methodologies for an integrated approach to coral health and reef assessment for Pacific and Caribbean reefs. Recent REU research has focused on the toxic effects of sunscreens on health of marine organisms, using sea urchin larvae as a model for the study of coral development and reef health.
REU intern Nina Sarmiento scoring urchin embryos
CofC = College of Charleston (housed in part at GML = Grice Marine Lab)
MUSC = Medical University of South Carolina
NIST = National Institute of Standards and Technology
NOAA = National Oceanographic and Atmospheric Administration (housed in part at CCEHBR = Center for Coastal Environmental Health and Biomolecular Research)
SCDNR = Department of Natural Resources (housed in part at MRRI = Marine Resources Research Institute)
HML = Hollings Marine Lab (houses members of all 5 partner institutions)