C. elegans culture. Unless otherwise specified, C. elegans hermaphrodite worms were cultured on NGM (normal growth media) agar plates with OP50 (Stiernagle, 2006). A full list of strains used in this study can be found in Extended Data Table 4-1. Xenopus laevis oocytes. Defolliculated Xenopus laevis oocytes were obtained from EcoCyte Bioscience and maintained in ND96 solution as follows (in mm): 96 NaCl, 1 MgCl2, 5 HEPES, 1.8 CaCl2, and 2 KCl, at 16°C for 3–7 d. Molecular biology.