Self-replication of DNA cross-tile patterns from temperature-selected species

Self-replication of species under selective pressures is crucial in biological evolution and diversity. Despite some successes with artificial selection and replication DNA systems, constructing a self-replication system under temperature selective pressure remains largely out of reach. In this work, we presented a temperature-responsive DNA origami system that selectively replicates a seed pattern in each replication cycle. Two dimer species with different conformations were constructed by incorporating a temperature-responsive module in the origami system (dimer AB at 25 °C and dimer AC at 45 °C). The dimer template serves as a seed to crystallize a ladder-like structure on cooling. The ladder structures were then cross-linked using T4 ligase and heated to yield the offspring dimers with identical conformation. The replication of temperature-selected origami dimers was demonstrated by agarose gel electrophoresis, AFM images, and fluorescence measurements. The proposed temperature-selective replication system contributes to fundamental studies of selection and evolution, as well as the design, fabrication, and directed evolution of nanomaterials.