Detecting Estrogen Pollution of the Stones River Waterways using the Yeast Estrogen Screen (YES)

Abstract

Estrogen is a steroid hormone, commonly associated with the female reproductive system. Estrogen is also used in the dairy and livestock industry as a muscle enhancer and to increase growth rates. Once in the environment, estrogen enters the estrogen transmission chain, and the effects have been connected to disruptions in waterway ecosystems. To gain a better understanding of local estrogen pollution, this study identified estrogen pollution levels for each of eleven sites in the Stones River Watershed using the Yeast Estrogen Screen (YES). Saccharomyces cerevisiae was engineered to carry one DNA (ERα) sequence, and five estrogen-responsive sequences (ERE). The ERE controls for the reporter gene, LacZ, which encodes for the enzyme β-galactosidase. The lysis buffer contains chlorophenol red-β-D-galactopyranoside (CPRG). When cleaved by β-galactosidase, it produces a colorimetric product. Through colorimetric and spectroscopic determination, samples that were collected either had no estrogen or low levels of estrogenic ligands present. Those that contained low levels of estrogen, Manson Pike Greenway Trailhead and Goochie Ford, need to be studied further