Originally published as Genetics Published Articles Ahead of Print on May 5, 2008.

Genetics, Vol. 179, 403-417, May 2008, Copyright © 2008
doi:10.1534/genetics.108.087221

Caenorhabditis elegans Genes Required for the Engulfment of Apoptotic Corpses Function in the Cytotoxic Cell Deaths Induced by Mutations in lin-24 and lin-33

Brendan D. Galvin, Saechin Kim1 and H. Robert Horvitz2

Department of Biology, Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139

2 Corresponding author: Department of Biology, Howard Hughes Medical Institute, Room 68-425, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139.
E-mail: horvitz{at}mit.edu

Two types of cell death have been studied extensively in Caenorhabditis elegans, programmed cell death and necrosis. We describe a novel type of cell death that occurs in animals containing mutations in either of two genes, lin-24 and lin-33. Gain-of-function mutations in lin-24 and lin-33 cause the inappropriate deaths of many of the Pn.p hypodermal blast cells and prevent the surviving Pn.p cells from expressing their normal developmental fates. The abnormal Pn.p cells in lin-24 and lin-33 mutant animals are morphologically distinct from the dying cells characteristic of C. elegans programmed cell deaths and necrotic cell deaths. lin-24 encodes a protein with homology to bacterial toxins. lin-33 encodes a novel protein. The cytotoxicity caused by mutation of either gene requires the function of the other. An evolutionarily conserved set of genes required for the efficient engulfment and removal of both apoptotic and necrotic cell corpses is required for the full cell-killing effect of mutant lin-24 and lin-33 genes, suggesting that engulfment promotes these cytotoxic cell deaths.


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Genetics 2008 179: NP. [Full Text]