Supplemental Materials for Mackiewicz et al., 2025

Among 959 somatic cells in C. elegans, there is the excretory gland cell, whose function remains unknown. The authors demonstrate that a specific family of secreted proteins, NSPCs, is expressed exclusively in this cell, enabling its targeted optogenetic ablation. Interestingly, the ablation of the excretory gland cell does not result in detectable physiological phenotypes, but it does cause global downregulation of NSPCs, suggesting that the primary role of this cell is the NSPC secretion. Surprisingly, the deletion of all 18 nspc genes also fails to produce strong phenotypes. However, transcriptomic analyses indicate that NSPCs may influence the insulin-like signaling pathway.