OhjausRNAta

OhjausRNAta, often referred to as guide RNA (gRNA) in English, is a short RNA molecule that directs a CRISPR-associated nuclease to a specific DNA sequence by base pairing with a complementary region. In natural bacterial CRISPR-Cas immunity, the guide function is provided by crRNA together with tracrRNA; engineered systems typically fuse these elements into a single-guide RNA (sgRNA) that combines targeting and scaffold features.

The targeting portion is usually about 20 nucleotides long, designed to be complementary to a genomic site adjacent to a protospacer adjacent motif (PAM). The rest of the molecule forms an RNA scaffold that binds the Cas enzyme. When complexed with Cas nucleases such as Cas9, the ohjausRNAta-Cas complex recognizes the target DNA and induces a double-strand break or performs alternative edits depending on the system.

Applications include gene disruption, knockout studies, transcriptional regulation (CRISPRi/CRISPRa), base editing, and prime editing; researchers design ohjausRNAta to target genes, regulatory elements, or noncoding regions. Design considerations include choosing specific target sites with minimal off-target potential, GC content, potential secondary structures, and choice of nuclease variant. Delivery can occur as DNA templates, in vitro transcribed RNA, or ribonucleoprotein complexes.

Safety and ethical considerations address off-target effects, immune responses, and regulatory oversight in clinical or environmental contexts. OhjausRNAta is a central component of CRISPR-based genome-engineering workflows and continues to be a focus of methodological optimization and regulatory discussion.