Myogenesis defect is specific to NOMO rather than general ER dysfunction. (A) Bright-field images showing myogenic differentiation over 4 days (day −3 to day 3) following siRNA-mediated knockdown of Nomo, Climp-63, calnexin, or Rtn3, with non-targeting (NT) control. Immunofluorescence images on day 3 show myotubes with Myhc (red) and DAPI (blue). Scale bar: 50 µm. (B) qPCR validation of knockdowns from A. (C) Quantification of the mean fusion index ± SD, representing the proportion of 2+ nuclei within Myhc-positive myotubes. N = 1,441 nuclei (siNT), N = 1,450 nuclei (siNomo), N = 1,653 nuclei (siClimp-63), N = 1,658 nuclei (siCalnexin), and N = 1,888 nuclei (siRtn3). Each condition was measured from n = 3 biological replicates. (D) Motility analysis measured by body bends per second (BBPS) of C. elegans challenged with either non-targeting (L4440) (n = 58) or nra-4–directed RNAi (n = 64). Data show mean ± SD from n = 3 biological replicates. Statistical analyses were performed using one-way ANOVA (C) or a two-tailed unpaired Mann–Whitney (D); ****P < 0.0001, **P < 0.01, and *P < 0.05. Source numerical data are available in source data.