Abstract

Like life itself, synthetic biology began with unicellular organisms. Early synthetic biologists built genetic circuits in model prokaryotes and yeast because of their relative biological simplicity and ease of genetic manipulation. With superior genetic tools, faster generation times, and better-understood endogenous gene expression machinery, prokaryotes and yeast were (and remain) appealing hosts for the engineering of synthetic systems. Now in its second decade, synthetic biology in unicellular organisms has produced myriad synthetic genetic circuits, a number of industrial applications, and fundamental new biological insights unlikely to have emerged from nonsynthetic approaches.