AbstractPhospholipase Cɛ (PLCɛ) is a novel class of phosphoinositide-specific PLC with unknown physiological functions. Here, we present the first genetic analysis of PLCɛ in an intact organism, the nematode Caenorhabditis elegans. Ovulation in C. elegans is dependent on an inositol 1,4,5-trisphosphate (IP3) signaling pathway activated by the receptor tyrosine kinase LET-23. We generated deletion mutants of the gene, plc-1, encoding C. elegans PLCɛ. We observed a novel ovulation phenotype whereby oocytes are trapped in the spermatheca due to delayed dilation of the spermatheca-uterine valve. The expression of plc-1 in the adult spermatheca is consistent with its involvement in regulation of ovulation. On the other hand, we failed to observe genetic interaction of plc-1 with let-23-mediated IP3 signaling pathway genes, suggesting a complex mechanism for control of ovulation.