Self-Replication, Exponential Growth and Evolutionary Selection of Artificial Systems
We want to make a “non-biological” system which can self-replicate. The idea is to design particles with specific and reversible and irreversible interactions, introduce seed motifs, and cycle the system in such a way that a copy is made. Repeating the cycle would double the number of offspring in each generation leading to exponential growth. Using the chemistry of DNA either on colloids or on DNA tiles made from three linked DNA helices, BTX, or on DNA origamis makes the specific recognition part easy. In the case of DNA BTX tiles we have in fact replicated the seed at least to the third generation, Nature 478, 227, (2011).
In more recent work we have used DNA origamis that can be permanently crosslinked using a UV activated molecule, CNV, on DNA sticky ends. This system needs no external intervention other than cycling temperature and light, mimicking daily cycles on earth. The system exponentially grows and through 24 doubling cycles has produced offspring multiplying the initial seed more than 7,500,000 times. We have also designed and produced colloidal particles that use novel “lock and key” geometries to get specific and reversible physical interactions. We even have initiated an elementary form of evolution and shown selection of one species over another. The process should be adaptable to assemble and replicate micro-nano constructs and devices.