Fragmentation (cell biology)

Apoptosis is the programmed destruction of cells, and the DNA molecules within them, and is a highly regulated process.

[10] Cellular and nuclear shrinkage, chromatin condensation and fragmentation, formation of apoptotic bodies and phagocytosis by neighboring cells characterize the main morphological changes in the apoptosis process.

Genes involved in controlling cell death encode proteins with three distinct functions:[12] The cleavage of chromosomal DNA into smaller fragments is an integral part, and biochemical hallmark, of apoptosis.

[14] CAD is usually inhibited by another protein in the cell, called Inhibitor of caspase-activated DNase (ICAD).

[15] In order for apoptosis to begin, an enzyme called caspase 3 cleaves ICAD so that CAD becomes activated.

CAD then cleaves the DNA between nucleosomes, which occur in chromatin at 180 base pair intervals.

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Cut that creates a sticky end
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Cut that creates a blunt end
Fragmentation is the third and final step of cell disassembly during apoptosis (right side of scheme). [ 9 ]
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A blood smear from a patient with hemolytic anemia, showing schistocytes