Study of the Effect of Tandem Promoters on Gene Expression

Synthetic biology enables bioengineers to generate biological systems that carry out a specified plan. Understanding factors that enable predictable gene regulation and expression can be useful for construction of predictable biological circuits in this field. In these experiments, we explore the effect of multiple consecutive lac promoters on gene expression. We measure the amount of Beta-galactosidase gene expression from plasmids that contain increasing numbers of lac promoters and combine experimental results with mathematical modeling. We find an increase from one to three promoters results in greater range of gene expression and a mathematical model generated based on experimental data predicts a further increase in number of regulation units results in further increase in gene expression range.