design and construction of a double inversion recombination switch for heritable sequential genetic memory设计、施工双反转复合开关的遗传序列遗传记忆.pdfVIP

Design and Construction of a Double Inversion Recombination Switch for Heritable Sequential Genetic Memory 1 2 1,2,3 1,2 Timothy S. Ham , Sung K. Lee , Jay D. Keasling , Adam P. Arkin * 1 Department of Bioengineering, University of California, Berkeley, California, United States of America, 2 Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America, 3 Department of Chemical Engineering, University of California, Berkeley, California, United States of America Abstract Background: Inversion recombination elements present unique opportunities for computing and information encoding in biological systems. They provide distinct binary states that are encoded into the DNA sequence itself, allowing us to overcome limitations posed by other biological memory or logic gate systems. Further, it is in theory possible to create complex sequential logics by careful positioning of recombinase recognition sites in the sequence. Methodology/Principal Findings: In this work, we describe the design and synthesis of an inversion switch using the fim and hin inversion recombination systems to create a heritable sequential memory switch. We have integrated the two inversion systems in an overlapping manner, creating a switch that can have multiple states. The switch is capable of transitioning from state to state in a manner analogous to a finite state machine, while encoding the state information into DNA. This switch does not require protein expression to maintain its state, and ‘‘remembers’’ its state even upon cell death. We were able to demonstrate transition into three out of the five possible states showing the feasibility of such a sw