Journal of Cell Biology, December 17, 2012 // JCB vol. 199 no. 7 1047-1055, doi: 10.1083/jcb.201209050
Apoptotic regulators promote cytokinetic midbody degradation in C. elegans
Yongping Chai, Dong Tian, Yihong Yang, Guoxin Feng, Ze Cheng, Wei Li, and Guangshuo Ou
National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
Cell death genes are essential for apoptosis and other cellular events, but their nonapoptotic functions are not well understood. The midbody is an important cytokinetic structure required for daughter cell abscission, but its fate after cell division remains elusive in metazoans. In this paper, we show through live-imaging analysis that midbodies generated by Q cell divisions in Caenorhabditis elegans were released to the extracellular space after abscission and subsequently internalized and degraded by the phagocyte that digests apoptotic Q cell corpses. We further show that midbody degradation is defective in apoptotic cell engulfment mutants. Externalized phosphatidylserine (PS), an engulfment signal for corpse phagocytosis, exists on the outer surface of the midbody, and inhibiting PS signaling delayed midbody clearance. Thus, our findings uncover a novel function of cell death genes in midbody internalization and degradation after cell division.