Programmed cell death and cell engulfment (WP2829)

Caenorhabditis elegans

Programmed cell death (PCD), or apoptosis, is an integral component of C. elegans development. During development, 131 cells are fated to die by apoptosis. PCD is easily observed with Nomarski optics in the C. elegans embryo; the nucleus of the apoptotic cell becomes refractile, resembling a flat button, making C. elegans an easy model for following apoptotic cell death. PCD in C. elegans can be divided into three main phases (with participating genes): specification of which cells should live or die (ces-1, ces-2, in general); activation of the cell killing machinery (egl-1, ced-9, ced-4 and ced-3); and an execution phase where the dying cell is dismantled and removed through phagocytosis (ced-1,-2,-5,-6,-7,-10 and-12), which occurs in concert with apoptotic DNA degradation (cps-6, nuc-1). Molecular and biochemical studies in C. elegans revealed programmed cell death mechanisms conserved in humans. The regulatory pathway that controls cell death is composed of conserved cell death activators and inhibitors: EGL-1 and BH3-domain-only proteins, CED-9 and Bcl-2, CED-4 and Apaf-1, and CED-3 and caspases, in nematodes and mammals, respectively. Further the degradation of chromosomal DNA involves a mitochondrial proapoptotic endonuclease: endonuclease G (EndoG), and AIF in mammals and their orthologs CPS-6 and WAH-1 in worms.


Karen Yook , Martina Summer-Kutmon , Eric Weitz , and Stefan Raats


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Caenorhabditis elegans



Pathway Ontology

apoptotic cell death pathway phagocytosis pathway

Cell Type Ontology

apoptosis fated cell


Label Type Compact Identifier Comment
CRN-1 GeneProduct wormbase:Y47G6A.8
CYP-13 GeneProduct wormbase:T10B9.8
CED-12 GeneProduct wormbase:Y106G6E.5
CRN-4 GeneProduct wormbase:AH9.2
WAH-1 GeneProduct wormbase:Y56A3A.32
CRN-5 GeneProduct wormbase:C14A4.5
CPS-6 GeneProduct wormbase:C41D11.8
EOR-2 GeneProduct wormbase:C44H4.7
TRA-1 GeneProduct wormbase:Y47D3A.6
CED-4 GeneProduct wormbase:C35D10.9
CED-9 GeneProduct wormbase:T07C4.8
CED-10/Rac1 GeneProduct wormbase:C09G12.8
CED-5/DOCK180 GeneProduct wormbase:C02F4.1
EOR-1 GeneProduct wormbase:R11E3.6
CES-1 GeneProduct wormbase:F43G9.11
HLH-2 GeneProduct wormbase:M05B5.5
CES-2 GeneProduct wormbase:ZK909.4
HLH-3 GeneProduct wormbase:T24B8.6
EGL-1 GeneProduct wormbase:F23B12.9
CED-9 GeneProduct wormbase:T07C4.8
CED-6 GeneProduct wormbase:F56D2.7
CED-1/SREC? GeneProduct wormbase:Y47H9C.4
CED-2/CrkII GeneProduct wormbase:Y41D4B.13
Active CED-3Protease GeneProduct wormbase:C48D1.2
CED-3 GeneProduct wormbase:C48D1.2
CED-7 GeneProduct wormbase:C48B4.4
CED-7/ABC1 GeneProduct wormbase:C48B4.4
PSR-1? GeneProduct wormbase:F29B9.4
CED-4 GeneProduct wormbase:C35D10.9
EGL-1 GeneProduct wormbase:F23B12.9
CED-4 GeneProduct wormbase:C35D10.9
CED-3 GeneProduct wormbase:C48D1.2
NUC-1 GeneProduct wormbase:C07B5.5
CRN-6 GeneProduct wormbase:K04H4.6
CRN-2 GeneProduct wormbase:CD4.2
CRN-3 GeneProduct wormbase:C14A4.4


  1. How the worm removes corpses: the nematode C. elegans as a model system to study engulfment. Gumienny TL, Hengartner MO. Cell Death Differ. 2001 Jun;8(6):564–8. PubMed Europe PMC Scholia
  2. Programmed cell death. Conradt B, Xue D. WormBook. 2005 Oct 6;1–13. PubMed Europe PMC Scholia