Organismal death is a process of systemic collapse whose mechanisms are less well understood than those of cell death. We previously reported that death in C. elegans is accompanied by a calcium-propagated wave of intestinal necrosis, marked by a wave of blue autofluorescence (death fluorescence). Here, we describe another feature of organismal death, a wave of body wall muscle contraction, or death contraction (DC). This phenomenon is accompanied by a wave of intramuscular Ca2+ release and, subsequently, of intestinal necrosis. Correlation of directions of the DC and intestinal necrosis waves implies coupling of these death processes. Long-lived insulin/IGF-1-signaling mutants show reduced DC and delayed intestinal necrosis, suggesting possible resistance to organismal death. DC resembles mammalian rigor mortis, a postmortem necrosis-related process in which Ca2+ influx promotes muscle hyper-contraction. In contrast to mammals, DC is an early rather than a late event in C. elegans organismal death. VIDEO ABSTRACT.
Keywords: ATP; C. elegans; aging; calcium; muscle; necrosis; organismal death; pathology; rigor mortis.
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