Seminars

　Advances in the first decade of 2000s, enabled not only to edit genes but pathways. Synthetic biologists developed gene circuits to carry out sophisticated functions in cells such as synthesis of complex molecules (artemisinin,
erythromycin, …), or biosensing. Gene synthesis and genome engineering technological advances have radically upgraded the scope of synthetic biology applications. Gene synthesis costs have dropped exponentially, and genetic engineering has flourished with a powerful repertoire of new technologies: MAGE, CRISPR/cas9. All these new tools have enabled researchers to address genome-wide properties which alter organism's most fundamental features such as genetic code, or transpecies differences.
　I will describe the work of our lab into the construction of a radically recoded E. coli strain (RC2) which uses 7 codons less. RC2 genome contains 64,000 bp changes in comparison to the reference strain. This level of engineering is 200-fold higher than any previous effort, and it will deliver a genetically isolated organism. RC2 will be resistant to viruses, and its DNA cannot be shared with other organisms as it has a unique synthetic genetic code. Parallel efforts in our lab have developed synthetic auxotrophies based on non-natural aminoacids (Mandel et al, Nature 2015). RC2 will be able to be used as a safe and biocontained microorganism. I will also mention, our efforts in mammalian genome engineering where we combine gene synthesis and CRISPR technologies to generate pigs with human physiological and immune compatibility that could be used as source for organ transplantation.