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

 

Tested Studies in Laboratory Teaching, 2018, Volume 39

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

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)