Department of Chemistry, New York University, New York, New York 10003, USA.
Nature. 2011 Oct 12;478(7368):225-8. doi: 10.1038/nature10500.
DNA molecules provide what is probably the most iconic example of self-replication--the ability of a system to replicate, or make copies of, itself. In living cells the process is mediated by enzymes and occurs autonomously, with the number of replicas increasing exponentially over time without the need for external manipulation. Self-replication has also been implemented with synthetic systems, including RNA enzymes designed to undergo self-sustained exponential amplification. An exciting next step would be to use self-replication in materials fabrication, which requires robust and general systems capable of copying and amplifying functional materials or structures. Here we report a first development in this direction, using DNA tile motifs that can recognize and bind complementary tiles in a pre-programmed fashion. We first design tile motifs so they form a seven-tile seed sequence; then use the seeds to instruct the formation of a first generation of complementary seven-tile daughter sequences; and finally use the daughters to instruct the formation of seven-tile granddaughter sequences that are identical to the initial seed sequences. Considering that DNA is a functional material that can organize itself and other molecules into useful structures, our findings raise the tantalizing prospect that we may one day be able to realize self-replicating materials with various patterns or useful functions.
DNA 分子提供了可能是最具标志性的自我复制例子——一个系统复制或自身拷贝的能力。在活细胞中，这个过程由酶介导，并自主发生，随着时间的推移，副本数量呈指数级增长，而无需外部干预。自我复制也已经在合成系统中得到实现，包括设计用于进行自我持续指数扩增的 RNA 酶。下一步令人兴奋的是在材料制造中使用自我复制，这需要稳健且通用的系统，能够复制和放大功能材料或结构。在这里，我们报告了朝这个方向的第一个进展，使用 DNA 瓦片图案，这些图案可以以预编程的方式识别和结合互补的瓦片。我们首先设计瓦片图案，使它们形成一个七瓦片的种子序列；然后使用种子来指导第一代互补的七瓦片女儿序列的形成；最后使用女儿序列来指导与初始种子序列完全相同的七瓦片孙女序列的形成。考虑到 DNA 是一种功能材料，可以将自身和其他分子组织成有用的结构，我们的发现提出了一个诱人的前景，即我们也许有一天能够实现具有各种图案或有用功能的自我复制材料。
