In the world of CRISPR/Cas9-based gene editing, HDR and NHEJ are two fundamental DNA repair pathways, each offering unique advantages. NHEJ provides speed and efficiency, …

Non-homologous end joining (NHEJ) is a pathway that repairs double-strand breaks in DNA. It is called "non-homologous" because the break ends are directly ligated without the need for a homologous template, in contrast to homology directed repair (HDR), which requires a homologous sequence to guide repair.

NHEJ vs HDR: Which repair pathway to repair CRISPR mediated double stranded breaks? In most eukaryotic cells, the non-homologous end joining (NHEJ) pathway generates insertions and deletions during double-stranded break (DSB) repair.

Mammalian cells preferentially employ NHEJ over HDR through several mechanisms: NHEJ is active throughout the cell cycle, whereas HDR is restricted to S/G2 phases; NHEJ is faster than HDR; and NHEJ suppresses the HDR process.

Feb 6, 2025 · Among these, Nonhomologous End Joining (NHEJ) and Homology-Directed Repair (HDR) are key pathways tasked with repairing double-strand breaks in DNA. Understanding …

Apr 16, 2015 · Here, we’ll discuss NHEJ, and how it impacts what happens to Cas9-mediated DSBs in the genome. Unlike HDR, NHEJ is active throughout the cell cycle and has a higher capacity for repair, as there is no requirement for a repair template (sister chromatid or homologue) or extensive DNA synthesis.

NHEJ is the canonical homology-independent pathway as it involves the direct ligation of sticky or blunt ends and often introduces small insertions and deletions along the way. HDR uses homologous sequence as a template for repair and is thus …

Mar 31, 2016 · HDR is a precise repair mechanism that uses homologous donor DNA to repair DNA damage, whereas NHEJ is an error-prone mechanism in which broken ends of DNA are joined together, often resulting in...

Apr 11, 2024 · When deciding between HDR and NHEJ for genome editing, researchers must consider the desired outcome of their experiments. HDR is suitable for precise genetic modifications and knockins, while NHEJ is preferred for gene knockout studies due to its ability to induce INDELs effectively.

At its core, NHEJ-break ends can be ligated without a homologous template, whereas HDR-breaks requires a template to guide repair. NHEJ is a very efficient repair mechanism that is most active in the cell.