Over the past several decades, sugar consumption has increased worldwide, contributing to the rise of obesity and type 2 diabetes. Both diseases are correlated with a variety of health problems, including a decrease in fertility. As in humans, a high-glucose diet decreases fertility in C. elegans. Although this has been shown by multiple labs, the cellular mechanisms that regulate this response to glucose are unknown. Glucose affects many cellular functions and pathways that could contribute to this decrease in fertility. One such pathway is the storage of glucose as glycogen, the main glucose storage polymer in both C. elegans and humans. We hypothesized that hermaphrodite C. elegans may have decreased fertility on a high-glucose diet because of an increase in glycogen storage. Both a high glucose diet and increased glycogen have been shown to have negative effects on lifespan in C. elegans (Gusarov et al. 2017; Seo et al. 2018). We found that decreasing glycogen storage using a mutant in the glycogen synthase enzyme (
gsy-1) led to an overall decrease in fertility in hermaphrodites; however, a high-glucose diet did not further reduce fertility in a
gsy-1 mutant. This suggests that glycogen storage plays a role in both lifespan regulation and fertility in C. elegans. A second pathway that may regulate the fertility response to a high glucose diet is apoptosis. Previously, it has been show that germline apoptosis increases in the C. elegans hermaphrodites in response to different environmental stressors. We hypothesized that glucose could act as an environmental stressor. We found that decreased hermaphrodite fertility on a high-glucose diet is dependent on the core apoptotic proteins CED-3 and CED-4. Currently, we are working to understand which apoptotic pathway is activated on a high-glucose diet. We have characterized this apoptosis response to glucose in both sexes and found it to be hermaphrodite specific. Through our work we hope to better understand the diverse cellular mechanisms which contribute to decreased fertility on a high-glucose diet.