The foundational concept behind splice-based editing involves the use of nucleases—enzymes that cleave DNA at designated sites. Early approaches included zinc finger nucleases (ZFNs), which pair engineered zinc finger domains with a nuclease to target specific DNA sequences. Another early method was transcription activator-like effector nucleases (TALENs), which use customizable DNA-binding domains derived from bacterial effectors. Both ZFNs and TALENs rely on inducing double-strand breaks (DSBs) to trigger repair processes, often resulting in insertions or deletions (indels) that can disrupt or modify gene function.
The most widely adopted splice-based technology today is the CRISPR-Cas9 system, which combines a guide RNA (gRNA) with the Cas9 nuclease to direct cleavage at precise genomic locations. CRISPR-Cas9’s simplicity, scalability, and efficiency have made it a cornerstone of modern genetic engineering. Variations of this system, such as base editing and prime editing, further refine its precision by enabling targeted nucleotide substitutions without inducing DSBs.
Applications of splice-based editing span fundamental biology, agriculture, and medicine. In research, these tools accelerate functional genomics by allowing rapid gene knockout or knock-in studies. In agriculture, splice-based methods have been used to enhance crop traits, such as disease resistance or nutritional value. In medicine, gene editing holds promise for treating genetic disorders, cancer, and infectious diseases by correcting mutations or introducing therapeutic genes. However, ethical considerations, off-target effects, and potential unintended consequences remain areas of ongoing debate and regulation.
Despite its transformative potential, splice-based editing continues to evolve, with advancements in delivery methods, improved specificity, and expanded toolkits broadening its applicability. As the technology matures, its integration into clinical and industrial practices is expected to grow, driving innovation across scientific disciplines.