Abstract
RNA-guided RNA 2'-O-methylation and pseudouridylation are naturally occurring processes, in which guide RNAs specifically direct modifications to rRNAs or spliceosomal snRNAs in the nucleus of eukaryotic cells. Modifications can profoundly alter the properties of an RNA, thus influencing the contributions of the RNA to the cellular process in which it participates. Recently, it has been shown that, by expressing artificial guide RNAs (derived from naturally occurring guide RNAs), modifications can also be specifically introduced into other RNAs, thus offering an opportunity to study RNAs in vivo. Here, we present strategies for constructing guide RNAs and manipulating RNA modifications in the nucleus.