Development of a Rapid Screening System of Environmental Estrogen Based on Recombinant Yeast Cell

ABSTRACT

Objective To develop a rapid screening method of environmental estrogen in vitro. Methods Estrogen responsive element (ERE) was inserted into the upstream of Lac Z (?-galactosidase ) reporter gene and the reporter gene was regulated under estrogen receptor(ER) in the recombinant yeast cells by the molecular biological technique. When the yeast cells was affected by environmental estrogen, conformational change of ER lead to expression through binding to ERE. There exist the functional relationships between the expression and the pollution degree of environmental estrogen. Therefore, the pollution degree can be reflected by assaying the activity of ?-galactosidase. Results It was identified by PCR that recombinant yeast cell, whose Lac Z reporter gene regulated under estrogen receptor, was successfully reconstructed. The experimental results showed that the time-dose-effect response had no significant changes when the recombinant yeast cell bad been exposed to ?-estradiol for 4 and 8 hours respectively; among the three methods of yeast disintegration, the ultrasonic vibration method had more advantage compared with that of the other methods and this dose-effect curve exhibited "S" shape; among 3 test chemical products, ?-estradiol was the most estrogenic activity, biosphenol A take second place, estradiol benzoate was the lowest. Conclusion The assay system of yeast cell for environmental estrogen hormone mediated by estrogen receptor is stable and applicable.