The expression of green fluorescent protein regulated by estrogen hormone in yeast cell

An estrogen transcription activation assay system using yeast cells was developed,which is sensitive,fast and easy to use in the routine screening of estrogen activity from chemical products according to the reporter gene of green fluorescent protein(GFP).The yeast reporter vector was constructed by inserting GFP into the CYC1 promoter downstream of pMP206/ERE and the lacZ gene in the reporter plasmid was substituted by GFP gene.DNA sequences revealed that CYC1-ERE-GFP frame from the reporter vector was correct.The estrogen receptor gene(hER cDNA) and GFP gene were found by PCR method in the tranformants.This exhibited that hER cDNA and GFP gene had been recombined into the yeast(cell.) A lot of participles that emitted green light were observed under the fluorescent microscope.This illustrated that GFP gene was expressed in the yeast cell.And incubation of yeast with various concentrations of estrogen led to expression of GFP in a dose dependent manner.Compared to other yeast assays,the yeast cell for environmental estrogen bioassay based on GFP reporter gene does not need cell wall disruption nor does it need the addition of a substrate.This GFP assay can be performed completely in 96 well plates.So it creates a cornerstone that can be used as a high throughput system for screening estrogenic chemical products.