Temperature Stressed Caenorhabditis elegans Males Prioritize Feeding over Mating Resulting in Sterility

Abstract

Heat stress negatively impacts fertility in sexually reproducing organisms at sublethal temperatures. These temperature stress effects are typically more pronounced in males. In some species, sperm production, quality, and motility are the primary cause of male infertility under temperature stress. However, this is not the case in the model nematode Caenorhabditis elegans where changes in mating behavior are the primary cause of fertility loss. We report that temperature stressed C. elegans males experience a dramatic upset in the balance of their food drive and their mating drive such that they prioritize feeding over mating. This change in priorities is due partially to increased expression of the chemoreceptor odr-10 in the AWA sensory neurons. Increased odr-10 expression in the presence of ample food demonstrates that males are unable to experience satiety, thus they never leave a food source and engage in mate searching behavior. These results demonstrate that moderate temperature stress may have profound and previously underappreciated effects on reproductive behaviors. As climate change associated temperature variability becomes more commonplace, it will be imperative to understand how temperature stress affects conserved behavioral elements critical to reproduction.