Regulation of Gene Expression Using Lac Z Reporter Gene: Expression of Gal 4-Activater Galactose Metabolism Genes with TATA/CATA Variant Elements at the Core Promoter in Saccaromyces cerevisiae

 

Farida Safadi-Chamberlain, Catherine Radebaugh, Xu Chen, & Laurie Stargell

Tested Studies in Laboratory Teaching, 2018, Volume 39

Abstract

Teaching the central dogma and gene expression to entry level Biology students is fundamental to Biology and Genetics courses. We introduced a laboratory exercise based on home-made yeast constructs where students study the role of promoters in gene expression using a Lac Z reporter system. Students measure the levels of b-galactosidase (b-gal) activity in four different Saccharomyces cerevisiae strains carrying plasmids with a Gal 4-inducible promoter fused to the prokaryotic Lac Z gene. Students then compare LacZ gene expression controlled by Gal4 promoter and four variants of the promoter consensus TATAAA sequence that drive variable levels of Lac Z expression. This laboratory exercise enforces student understanding of the components of gene expression and the importance of conserved promoter sequences in gene expression, provides them with hands-on experience in performing the galactosidase enzyme assay, and gives them the opportunity to work with the model eukaryotic organism, yeast.

Keywords:  lac Z reporter gene, reporter gene, Genetics, gene expression, TATA promoter element, TATA Binding Proteins (TBP), Gal 4 regulon, Saccaromyces cerevisiae, genetics laboratory exercise

University of Wisconsin, Madison (2017)