NMY-1 and NMY-2 affect cellularization in the C. elegans hermaphrodite gonad. (A) Schematic of a cross section of one side of a wild-type hermaphrodite gonad, showing the U-shape with distal and proximal ends, nuclei (gray dots), lateral membrane growth (arrowheads), the central shared cytoplasm (rachis), the spermatheca (S), and a fertilized egg. Sperm, located in the spermatheca, are omitted for clarity. The region near the bend (gray box) is shown in subsequent micrographs. The region at the rachis opening (black box) was used for ring channel (arrows) measurements throughout this work. (B–D) Fluorescent micrographs of GFP::PH, a membrane marker, expressed in wild-type gonads treated with RNAi for 48 h. (B) Empty vector RNAi control treatment: maximum projection of three Z-sections spaced at 1.5 μm. The well-formed rachis is visible in two locations (arrowheads; n = 8). (C) nmy-1(RNAi) treatment: maximum projection of three Z-sections spaced at 1.5 μm, showing premature cellularization and lack of a rachis (n = 9). (D) nmy-2(RNAi) treatment: maximum projection of 10 Z-sections spaced at 1.5 μm, showing a complete lack of membranous structures and loss of cellularization (n = 11). Scale bars, 10 μm.