Project description:We used the mummichog (Fundulus heteroclitus) array we developed to test whether our arrays could be used to monitor the efficacy of remediation at an estuarine Superfund site. Shipyard Creek is a chromium-contaminated Superfund site in Charleston, SC undergoing remediation, therefore it provides a unique opportunity to study the efficacy of arrays as a molecular biomarker in of toxicant effects in mummichogs. Mummichogs were captured in Shipyard Creek in Charleston, SC prior to remediation (2000), after remediation began (2003), and as remediation further progressed (2005). Simultaneously, mummichogs were collected from a reference site at the Winyah-Bay National Estuarine Research Reserve (NERR). The hepatic gene expression pattern of fish captured at Shipyard Creek showed wide differences from the fish captured at NERR in 2000. As remediation progressed the gene expression pattern of fish captured at Shipyard Creek became increasingly similar to fish captured at NERR, and the number of genes differently expressed dropped from 22 to 4. The magnitude of differential gene expression of the individual genes also decreased during remediation. The recovering gene expression profile is associated with lower chromium bioavailability, demonstrated through significantly decreased body burden and sediment concentrations. For example, sediment concentrations at Shipyard Creek were 80-fold greater than NERR in 2000, 51-fold greater in 2003, and only 8-fold greater in 2005. However, hydraulic dredging in 2005 stirred up the sediments and increased body burden of chromium even though chromium sediment concentrations continued to drop. Therefore, the number of differentially expressed genes increased to 9. Overall, the data supports our hypothesis that arrays can be used to monitor site mitigation, as the number of genes differentially expressed mimics the body burden and also indicates when on-site remediation is increasing bioavailability. Keywords: Field site

Project description:The goal of this study was to use global gene expression as a diagnostic tool to compare hepatic gene expression patterns in both male and female FHM in streams with the lowest and highest reproductive success, and potentially identify a suite of mRNA transcripts indicative of reproduction in a population The goal of this study was to compare differences in hepatic mRNA expression between gender at high and low egg-producing streams, not differences between individual streams. A k-means cluster analysis was performed using eggs/pair/day on the original 17 streams to delineate 3 clusters: high, medium and low. From that analysis, FHM from 6 of the original 17-streams used in Crago et al. (2010) were chosen for the microarray experiment (Fig. 1, Table 1). In this study the experimental condition is reproductive success; High versus Low reproductive success. The streams grouped into High Reproductive Success were Oak Creek-2007 (2313 eggs), Point Creek (1277 eggs), Meeme Creek (1164 eggs) and Baird Creek (967 eggs). The streams grouped into Low Reproductive Success were: Ashwaubenon Creek (0 eggs), Devils Creek (541 eggs) and Oak Creek-2006 (642 eggs). Multiple regression analysis using the 22 sediment and water quality characteristics measured in the 6 streams with the highest (n = 4 and lowest (n = 3) streams demonstrated that there were no differences amongst the streams in regards to measure sediment and water variables. .5 One array was run for each gender from each stream. So that Males from Point Creek were pooled and run on one array, males from Ashwaubenon Creek were run on a separate array, and so forth. There were 14 arrays used in this study, 7 for males, 7 for females from individual rivers. So that Males from Point Creek were pooled and run on one array, males from Ashwaubenon Creek were run on a separate array, and so forth. In the case of Oak Creek, which was sampled in both years, there was a large difference in egg production between two years. Therefore separate arrays were run for Oak Creek 2006 and Oak Creek 2007. All streams chosen had overall survival rates of at least 80% through the 21-day sampling period, except Devils River. The survival rate for Devils River was at 100% until four days prior to the end of the experiment when six fish died or escaped.

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