CUR - The Council on Undergraduate Research

Raising Aquatic Vertebrates in Impaired Waters Causes a Mis-expression of Genes Leading to Developmental Malformations

Cecily Hayek, Dorian Tignor, and Dr. Wade Znosko Longwood University, 201 High Street, Farmville, VA 23909

The presence and amount of coliform bacteria have been used as environmental risk indicators for the occurrence of fecal-associated human pathogens (e.g., Salmonella, enteric viruses, etc.) since the early 20th century. Many studies have reported on the relationship between coliform indicators and the overall quality of water sources for human public use and recreation. Our current study utilizes to a long-term water monitoring program within the Appomattox River watershed of south central Virginia, as it examines the effect of raw water containing varying bacteria levels on the first 72 hours of aquatic vertebrate development, using a zebrafish model. Water samples were obtained from a variety of freshwater collection sites both considered ‘clean’ and ‘impaired’ by the VA Department of Environmental Quality (‘impaired’ includes > 238 fecal coliforms/100mL across multiple samplings). Other physical parameters were similar between sample sites. Using qRT-PCR we were able to track changes in genetic expression of 96 genes within 10 developmental pathways. Comparisons of gene expression within the WNT, p53, and JAK STAT pathways between a “clean” water source and an impaired water source have shown variation in gene expression compared to control. Using this data, we were able to phenotypically examine the effects that this alteration of gene expression had on critical developmental pathways and thus overall proper development of the organism. Using in situ hybridizations we have determined that embryos raised in impaired waters displayed mis-expression of genes within the WNT and JAK STAT developmental pathways, which lead to an overall malformation in development of particular organs, specifically brain and heart. This analysis provides more insight of the negative effects of impaired waters on the development of aquatic organisms. Funding provided by Longwood University Faculty Research Grant.

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