Matricide in Caenorhabditis elegans as an example of programmed death of an animal organism: The role of mitochondrial oxidative stress

摘要

Nematode Caenorhabditis elegans is a widely used model for studying genetic and molecular mechanisms of lifespan regulation. The choice between two life strategies-normal aging and matricide (programmed death)-made by an adult hermaphroditic C. elegans organism is based on food availability and is also affected by different kinds of stress. We have tested a hypothesis concerning an increase in matricide probability as a result of oxidative stress; this hypothesis is based on the phenoptosis theory. High concentrations of paraquat, a strong mitochondrial stressor, were shown to increase matricide propensity. Mutants with a decreased antioxidant potential of mitochondria (nnt) were more sensitive to the reagent. On the other hand, paraquat concentrations required for this effect to be observed are toxic for the progeny, whereas at low paraquat concentration matricide frequency is the same in wild-type worms and nnt mutants. Therefore, one can assume that the molecular mechanisms of matricide initiation under normal conditions are not necessarily connected to mitochondrial oxidative stress.