Apoptotic DNA fragmentation

White DNA bands against a dark grey background, resembling the rungs of a ladder
Apoptotic DNA fragmentation, visualised by the DNA laddering assay (left). A 1 kb marker (middle) and control DNA (right) are included for comparison.

Apoptotic DNA fragmentation is a key feature of apoptosis, a type of programmed cell death. Apoptosis is characterized by the activation of endogenous endonucleases, particularly the caspase-3 activated DNase (CAD),[1] with subsequent cleavage of nuclear DNA into internucleosomal fragments of roughly 180 base pairs (bp) and multiples thereof (360, 540 etc.). The apoptotic DNA fragmentation is being used as a marker of apoptosis and for identification of apoptotic cells either via the DNA laddering assay,[2] the TUNEL assay,[3][4] or the by detection of cells with fractional DNA content ("sub G1 cells") on DNA content frequency histograms e.g. as in the Nicoletti assay.[5][6]

  1. ^ Sakahira, H; Enari, M; Nagata, S (January 1998). "Cleavage of CAD inhibitor in CAD activation and DNA degradation during apoptosis". Nature. 391 (6662): 96–9. Bibcode:1998Natur.391...96S. doi:10.1038/34214. PMID 9422513. S2CID 4329685.
  2. ^ Wyllie AH (1980-04-10). "Glucocorticoid-induced thymocyte apoptosis is associated with endogenous endonuclease activation". Nature. 284 (5756): 555–556. Bibcode:1980Natur.284..555W. doi:10.1038/284555a0. ISSN 0028-0836. PMID 6245367. S2CID 4318802.
  3. ^ Gorczyca, W; Bruno, S; Darzynkiewicz, R; Gong, J; Darzynkiewicz, Z (Nov 1992). "DNA strand breaks occurring during apoptosis - their early insitu detection by the terminal deoxynucleotidyl transferase and nick translation assays and prevention by serine protease inhibitors". Int J Oncol. 1 (6): 639–48. doi:10.3892/ijo.1.6.639. PMID 21584593.
  4. ^ Gavrieli, Y.; Sherman, Y.; Ben-Sasson, S. A. (1992). "Identification of programmed cell death in situ via specific labeling of nuclear DNA fragmentation". The Journal of Cell Biology. 119 (3): 493–501. doi:10.1083/jcb.119.3.493. PMC 2289665. PMID 1400587.
  5. ^ Nicoletti I, Migliorati G, Pagliacci MC, Grignani F, Riccardi C (3 June 1991). "A rapid and simple method for measuring thymocyte apoptosis by propidium iodide staining and flow cytometry". Journal of Immunological Methods. 139 (2): 271–279. doi:10.1016/0022-1759(91)90198-O. PMID 1710634.
  6. ^ Riccardi C, Nicoletti I (9 November 2006). "Analysis of apoptosis by propidium iodide staining and flow cytometry". Nature Protocols. 1 (3): 1458–1461. doi:10.1038/nprot.2006.238. PMID 17406435. S2CID 4469406.