Cooperative Ecosystem Studies Unit, South Florida/Caribbean CESU

The summary for the Cooperative Ecosystem Studies Unit, South Florida/Caribbean CESU grant is detailed below. This summary states who is eligible for the grant, how much grant money will be awarded, current and past deadlines, Catalog of Federal Domestic Assistance (CFDA) numbers, and a sampling of similar government grants. Verify the accuracy of the data FederalGrants.com provides by visiting the webpage noted in the Link to Full Announcement section or by contacting the appropriate person listed as the Grant Announcement Contact. If any section is incomplete, please visit the website for the Geological Survey, which is the U.S. government agency offering this grant.

Cooperative Ecosystem Studies Unit, South Florida/Caribbean CESU: The purpose of the Columbia Environmental Research Center (CERC) funding opportunity is to collaborate with a team of molecular biologists in the investigation of intersex in largemouth bass using a bass-specific DNA microarray. The overall goal of this collaborative project is to assess the biological mechanisms for the development of EDC-induced intersex in fish. Specifically, we will develop gene expression biomarkers in tissues along the HPG-axis of largemouth bass exposed to ethinyl estradiol. The proposed project will consist of five primary tasks: 1) Induce intersex in largemouth bass with ethinyl estradiol; 2) Monitor the development of the intersex in the gonads of the LMB over a chronic exposure period through histological examinations; 3) Measure global gene expression profiles in target tissues of the HPG-axis with a LMB-specific DNA microarray; 4) Select gene expression biomarkers indicative of the genotypic and phenotypic changes observed in intersex in largemouth bass; and 5) Develop testable hypotheses for potential biochemical pathways and cellular mechanisms leading to the condition of intersex in largemouth bass. Largemouth bass (juvenile or sub-adults) will be obtained from a hatchery and placed in 0.1 acre outdoor ponds at the CERC. Bass will be dosed at the CERC with ethinyl estradiol at a concentration expected to induce intersex. The liver, hypothalamus, pituitary, and gonads of male and female bass will be sampled each month over the course of a chronic exposure. The development of intersex will be evaluated by histology. The duration of the exposure will continue until the frank development of the hermaphroditic condition is observed in the bass. Selected tissues collected over the course of the exposure will subsequently be evaluated for alterations in global gene expression with a largemouth bass-specific DNA microarray. Gene expression profiles will be compared between exposed and unexposed bass, between individuals which develop intersex and those from groups that do not develop intersex, and last, within individuals which develop intersex. A profile or "fingerprint" of the gene expression pattern indicative of intersex in exposed bass will be identified. Selected genes that appear to be characteristic of the intersex condition in estrogen-exposed bass will be further characterized by alternate methods (qPCR). Major biochemical pathways that are disrupted will be identified and hypotheses developed for confirmation studies of the ability of those genes to predict intersex in largemouth bass. Chemical disruption of endocrine systems in fish has been a topic of intense public interest over the past two decades. As a consequence of more intense research and monitoring, biologists have documented endocrine and reproductive dysfunction in wild populations of fish and wildlife across the country and across the world. In parallel, environmental chemists have documented the presence of endocrine disrupting chemicals (EDCs) in both ground and surface waters of the US (Kolpin et al. 2000). Through these efforts, EDCs have been observed in numerous locations, associated with municipal wastewaters, industry, agriculture, animal production operations, and urbanization. Measures of endocrine function in fish and EDCs in aquatic environments have both been important to document the potential for endocrine disruption in fish (and wildlife) from chemicals. Yet, the presence of these chemicals and the presence of endocrine-related disruption in fish, even together, do not provide the required evidence to establish causal linkages among these factors. EDCs in the environment have been the subject of federal research and regulations. Laboratory testing protocols to screen chemicals for their ability to alter normal endocrine function in fish, birds and mammals have been under development (Food Quality Protection Act of 1996) and progress on these testing methods has been steady. However, the large majority of the existing data on EDCs and endocrine-related effects in wild populations has been monitoring occurrence and not designed to evaluate causality or substantive effects on populations. The causal link between aberrant endocrine function and presence of putative EDCs has been an evolving research effort. The general measurements of endocrine disruption in fish (biomarkers) have been biochemical, physiological, and histological in nature. These include measurements of altered sex steroid, elevated plasma vitellogenin in males, and most notably "intersex" condition of fish gonads. Moreover, if endocrine-related effects in fish are attributable to EDCs, we must be able to understand the extent of adverse effects, particularly as they relate to population dynamics and our management strategies for fish populations. Thus, we need to understand what is natural for these populations of fish. Intersex in fish, for example, may be genetically based (ie. species-specific), related to environmental conditions (eg. temperature), or due to exposure to chemicals (eg. estrogen mimics). Thus, the natural occurrence of intersex in fish must be determined, as well as the mechanisms for development of intersex from these different factors. We must be able to distinguish if an intersex phenotype is due to a natural cause, such as species-related factors, or some unnatural factor, such as an EDC. Currently, our knowledge of intersex in fish, the causes of intersex, and the outcomes of intersex on fish populations does not allow us to know if it serves as a signal or warning for potential adverse effects on wildlife or humans. The investigations described below are designed to begin to address some of these fundamental questions regarding intersex in fish. The CERC provides scientific information and data to address national and international environmental issues related to aquatic and terrestrial ecosystems. The CERC has a unique capability for conducting multidisciplinary research in the area of aquatic toxicology. Scientists at CERC form partnerships with scientists at national, state, and local agencies, non-governmental organizations and universities to produce the scientific information required for management of the nations resources. The CERC produces and disseminates scientific information needed for decision-making in collaboration with Federal and State resource management agencies, Native American tribes, academic institutions, and organizations.