Synthetic biologists seek to design, build, and test novel biological systems. We have chemically synthesized a bacterial genome (Mycoplsama mycoides, 1078Kb) and brought it to life by transplantation into the cytoplasm of a related species. We are interested in reducing the gene content of this “synthetic cell” to help us understand the minimal requirements for simple cellular life. Using Tn5 transposon mutagenesis we have identified 438 genes that are apparently non-essential out of a total of 911 genes. Using this information, we have designed reduced versions of 8 overlapping segments of the genome. We have now built and tested each of the 8 reduced segments, and they are all viable in the context of the remaining 7/8th wild type genome. When all 8 of the reduced segments are combined, the resulting reduced genome is not viable. However, several combinations of reduced segments are viable. We are now refining our design so as to achieve a viable cell containing all 8 of the reduced segments.
1. Lartigue C, Vashee S, Algire MA, Chuang RY, Benders GA, Ma L, Noskov VN, Denisova EA, Gibson DG, Assad-Garcia N, Alperovich N, Thomas DW, Merryman C, Hutchison CA III, Smith HO, Venter JC, Glass JI. (2009) Creating Bacterial Strains from Genomes that have been Cloned and Engineered in Yeast. Science, advance online publication doi:10.1126/science.1173759.
2. Gibson DG, Glass JI, Lartigue C, Noskov VN, Chuang RY, Algire MA, Benders GA, Montague MG, Ma L, Moodie MM, Merryman C, VAshee S, Krishnakumar R, Assad-Garcia N, Andrews-Pfannkoch C, Denisova EA, Young L, Qi ZQ, Segall-Shapiro TH, Calvey CH, Parmar PP, Hutchison CA 3rd, Smith HO, Venter JC (2010). Creation of a bacterial cell controlled by a chemically synthesized genome. Science 329, 52-56.