Genomic DNA loci specified by guide RNA (gDNA target)

Genomic DNA loci specified by guide RNA are the specific nucleotide sequences within the genome targeted for modification by CRISPR-Cas gene-editing technologies. These loci are identified by a synthetic guide RNA (gRNA) that directs a Cas nuclease (such as Cas9 or Cas12a) to a complementary DNA sequence, typically located near a protospacer adjacent motif (PAM) (Doudna & Charpentier, 2014, Science). Once bound, the nuclease induces a double-strand break or performs chemical modification, triggering cellular repair mechanisms like non-homologous end joining (NHEJ) or homology-directed repair (HDR) to alter the genetic code (Hsu et al., 2014, Cell). This technology is therapeutically employed to knock out disease-causing genes, correct mutations, or modulate regulatory elements, as seen in the FDA-approved treatment exagamglogene autotemcel for sickle cell disease (FDA, 2023). The precision of targeting these loci is paramount, as unintended binding to similar sequences elsewhere in the genome can lead to off-target effects and potential oncogenic transformations (Fu et al., 2013, Nature Biotechnology). Consequently, the selection and validation of these genomic targets are central to the safety and efficacy of CRISPR-based therapeutics.

Other names

Target DNA sequenceProtospacerCRISPR target siteGenomic target locus

Targeted genomic DNA cleavage or modification via CRISPR-Cas systems to induce gene knockout, correction, or regulation.