Evaluating Gene Expression of Winter Flounder (Pseudopleuronectes americanus) Across a Gradient of Contaminant and Sewage Loadings in Long Island, NY

Inshore winter flounder (Pseudopleuronectes americanus) populations in New York coastal waters have reached record low numbers in recent years, with recruitment into the fishery likely limited by survival of post-settlement juvenile fish. In order to identify cellular pathways associated with site-specific variation in condition and mortality, we examined differential mRNA expression in juvenile winter flounder collected from six different bays across a gradient in human population density and sewage inputs in Long Island, NY. RNA-sequencing of flounder from contrasting sites was used to guide choice of gene targets. Analysis of a suite of 9 genes related to contaminant response, immune response, and glucose/glycogen metabolism by qPCR revealed complex patterns in expression, revealing associations among genes, site specific differences and statistically significant correlations with growth rate using hierarchical linear models. Current work is examining additional transcripts including those associated with response to hypoxia, oxidative stress, and cell division/apoptosis regulation. These additional genes will be included in modeling efforts to identify other cellular pathways that influence daily growth of juvenile winter flounder. Our goal is to provide a more complete picture of altered physiologic state associated with growth and condition in these impacted populations.