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- 1996-1998 Projects »
- 1994-1996
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Marine Biotechnology
1996-1998 Projects
Molecular Biomarkers of Chemical Sensitivity
in Protected Species: A New Approach to Environmental Risk Assessment
Mark Hahn and Brenda Jensen, Woods Hole Oceanographic Institution
Planar halogenated aromatic hydrocarbons (PHAH), including PCBs
and dioxins, are ubiquitous and persistent contaminants of the global
environment. Certain species of seals and whales have some of the
highest levels of these pollutants documented in any animal group
due, in part, to their position at the top of the food chain, and
because PHAH tend to accumulate in the blubber of these animals.
These compounds have been suggested as contributing to marine mammal
mortality and morbidity, but the magnitude of the risk that PHAH
pose to the health of marine mammals is controversial. The sensitivity
of these animals to PHAH is not easily measured, since legal and
ethical concerns preclude the direct testing of toxic chemicals
on protected animals such as marine mammals. In this Sea Grant-supported
project, researchers will determine the dioxin and PCB sensitivity
of whales (including the beluga, Delphinapterus leucas) by characterizing
a protein that is critical to PHAH effects. Through DNA cloning
and in vitro analysis of the aryl hydrocarbon receptor protein,
investigators hope to better understand the sensitivity of beluga
and other whales to these pollutants. This state-of-the-art technique,
commonly used to study human sensitivity to toxics, will aid the
evaluation of the beluga's risk to PHAH and will serve as a model
for a new method for assessing protected animals' risk to environmental
contaminants. (R/B-137)
Development of Species-Specific and Stage
Specific Immunofluorescent Markers for Bivalve Larvae with an Application
to Fisheries Management
Cheryl Ann Butman and Elizabeth Garland, Woods Hole Oceanographic
Institution
Waters surrounding Nantucket Island, MA are known sinks for late-stage
larvae of commercially-important bivalves such as Argopecten irradians
(bay scallop), Mya arenaria (soft shell clam), and Spisula solidissima
(surf clam). The planktonic larval stage is an important part of
the life history of a benthic invertebrate as it is only during
this stage that the organisms disperse, and thus exchange genes
among populations, colonize new habitats or replenish old ones.
However, limitations in sampling and identification of these planktonic
organisms often hamper research and management practices. In this
study, larvae will be sampled using a newly designed, automated
sampling tool--the MASZP (moored, automated, serial zooplankton
pump). Employing a cutting-edge molecular technique, the collected
larvae will then be marked with fluorescent antibody tags to facilitate
detection, identification, and enumeration in the samples. Identifying
and enumerating previously indistinguishable planktonic larvae at
early stages of their life cycle will be invaluable in studies of
factors controlling population distributions, and of fisheries and
aquaculture management. (R/B-139)
The following four projects are part of
a 7-project, multi-institutional initiative supported by the National
Sea Grant College Program titled "Chemical/Biological Interactions:
Receptor-Mediated Effects on Reproduction and Development in Aquatic
Species."
Fish Cytochrome P450 Genes Involved in Chemical
Effects
John Stegeman, Woods Hole Oceanographic Institution
In this study, researchers will establish a molecular basis for
explaining and monitoring effects of anthropogenic or natural chemicals
on endocrine and developmental processes in fish. Through studying
the salt marsh minnow, Fundulus heteroclitus, investigators will
clone and sequence genes for cytochrome P450 that may metabolize
and activate or inactivate chemical compounds. These studies will
provide a molecular foundation for understanding the mechanisms
and monitoring the effects of diverse chemical pollutants. The results
will have implications for and applications in ecology, toxicology
and pharmacology of fish, and could provide new approaches for screening
effluents and new chemicals for biological reactivity. (R/P-60)
Molecular Biological Approaches for Non-Destructive
Assessment of Chemical Effects on Marine Mammals
John J. Stegeman and Michael J. Moore, Woods Hole Oceanographic
Institution
Pollutants in the marine environment, such as polynuclear aromatic
hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), dioxins,
and furans, are believed to have adverse affects on marine populations,
including marine mammals. Exposure to such pollutants may effect
the physiology of marine mammals, including reproduction, immune
defense, endocrine system functions, and, possibly, neural systems
that control social and migratory behavior. Using molecular biological
techniques, researchers in this study will focus on the pilot whale,
studying biopsy samples of free-ranging populations as well as archived
samples taken from stranded whales to evaluate the exposure of marine
mammals to harmful chemical compounds. By quantifying expression
of the cytochrome CYP1A gene, a sensitive biomarker of hydrocarbon
effects, in the livers and other organs of the pilot whale, investigators
will be able to characterize metabolic activity. The methods established
in this study will provide a non-destructive means to study compounds
that may pose a threat to fragile marine mammal populations. (R/P-61)
Impact of Environmental Contaminants on
an Aquatic Bird Population
Mark E. Hahn and Connie Hart, Woods Hole Oceanographic Institution
and Ian Nisbet, I.C.T. Nisbet and Co.
Many questions surround the extent to which dioxin-like compounds
and chlorinated pesticides disrupt endocrine functions--such as
reproductive and developmental processes--in humans and aquatic
animals, including birds. This project seeks to examine abnormalities,
including gonadal feminization, in common tern embryos from two
coastal Massachusetts sites with different levels of environmental
contamination. Using chemical, biochemical, and immunohistochemical
methods as well as cell-culture bioassays, researchers will measure
exposure of the birds to a variety of environmental pollutants.
Through a combination of field and laboratory-based studies, investigators
hope to assess possible relationships between health effects and
specific contaminants, including dioxin-like compounds and environmental
estrogens. (R/P-58)
Identification of Bioactive Marine Natural
Products Using a Fish Culture Bioassay
Mark Hahn, Woods Hole Oceanographic Institution
Marine organisms produce a variety of organic compounds, some of
which display useful biological activities. Many of these products
are structurally related to dioxins, PCBs and other anthropogenic
compounds that act through specific receptor-mediated mechanisms.
Investigators in this study will use a newly-devised cell culture
bioassay system to determine marine natural products that stimulate
or inhibit the same biochemical systems that respond to dioxins.
Exploring the mimicking effects of natural marine compounds will
be important in understanding the biochemical and physiological
changes that have been observed in animals living in contaminated
environments. In addition, identification of these compounds may
be useful as future research tools or as pharmaceutical agents.
(R/B-124)
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