induction of barnase (death gene) reduces cell growth

We characterized the activity of Barnase on an inducible plasmid constructed by UC Berkeley for iGEM 2007 (parts BBa_I716408C and BBa_I716211). This construct works by expressing background levels of Barstar with in the presence of an inducible Barnase. When induced, Barnase will overwhelm Barstar. Higher levels of Barnase expression resulted in lower rates of growth in the bacteria, affirming the principle of Barnase-based growth control for the genetic fence, and confirming the results from Berkeley 2008. We characterized the growth repression of Barnase under a range of arabinose inducer concentrations.

Our results show that expression of Barnase is effective in reducing cell growth, suggesting that Barnase will enable the genetic fence to prevent growth of iGarden plants outside of their designated areas.

barnase growth control in E. Coli   [click to enlarge]