Modulation of C. elegans behavior, fitness, and lifespan by AWB/ASH-dependent death perception.

The ability of the nervous system to initiate intricate goal-directed behaviors in response to environmental stimuli is essential for metazoan survival. In this study, we demonstrate that the nematode Caenorhabditis elegans perceives and reacts to dead conspecifics. The exposure to C. elegans corpses, as well as corpse lysates, activates sensory neurons AWB and ASH, triggering a glutamate- and acetylcholine-dependent signaling cascade that regulates both immediate (aversion) and long-term (survival) responses to the presence of a death signature. We identify increased adenosine monophosphate (AMP) and histidine concentrations as potential chemical fingerprints for the presence of metazoan corpses and show that death cue sensing by AWB and ASH leads to physiological changes that promote reproduction at the expense of lifespan. Our findings illuminate a signaling paradigm that allows organisms to detect and interpret the environmental enrichment of intracellular metabolites as a death cue.