Expanding nucleic acid function in vitro and in vivo.

Nucleic Acids composed of the five natural bases and a phosphate backbone can be designed or evolved to have a wide variety of sequence-dependent functions. Recent in vitro work has addressed some outstanding issues in evolving nucleic acid catalysts, as well as the creation of prescribed shapes and arrays from oligonucleotides and long single-stranded nucleic acids. Nucleic acids have also been engineered in vivo, leading to new modes of gene regulation. It is likely that the improving ability to synthesize long DNA sequences will accelerate the creation of novel functions from nucleic acids.