RNA-targeting CRISPR systems from metagenomic discovery to transcriptomic engineering

Deployment of RNA-guided DNA endonuclease CRISPR-Cas technology has led to radical advances in biology. As the functional diversity of CRISPR-Cas and parallel systems is further explored, RNA manipulation is emerging as a powerful mode of CRISPR-based engineering. In this Perspective, we chart progress in the RNA-targeting CRISPR-Cas (RCas) field and illustrate how continuing evolution in scientific discovery translates into applications for RNA biology and insights into mysteries, obstacles, and alternative technologies that lie ahead.