Recent Advancements in Programmed Nucleases for Genome Editing

Genome editing is preformed using molecular scissors called nucleases including zinc-finger nucleases (ZFNs), transcription activators like effector nucleases (TALENs) and clustered regularly interspaced short palindromic repeats (CRISPR)–CRISPR-associated (Cas) system (CRISPR/Cas9), single-stranded oligo DNA nucleotides (ssODNs). Programmed nucleases are highly advanced and powerful molecular engineering tools to study various biological aspects and improve our understanding towards underlying mechanisms of different physiological processes. Here, we present the recent advancements in conventional and modern genome editing technologies involved in the engineering of metabolic pathways, transgenic organisms, functional screening of genomes and treatment of diseases at the molecular level. The focus is to compare gene editing efficiencies of different systems in terms of eliminating random integration events and generate precisely targeted and stable systems. Recent approaches for efficient optimisation of CRISPR-Cas9 tool and their impact on the consequences of gene editing have been discussed.