Fig. 3: DRP1 loss leads to SAC defects and premature chromosome separation.

a Kinetochore configurations in control or DRP1 null oocytes. White arrows indicate the compact kinetochores, and green arrows indicate the fragmented kinetochores. b The occurrence frequency of kinetochore morphology in (a) in three independent replicates. c Measurement of inter-sister kinetochore distance of MI bivalents in (a). Three independent replicates were performed. d Chromosome configurations of control or DRP1 null oocytes at MI and MII stages. Enlarged images show representative chromosomes. e The occurrence frequency of chromosome morphology in (d) in eight independent replicates. f MI stage oocyte microinjected with TRIM21 + IgG or TRIM21 + anti-DRP1 were stained for REC8 (red). Enlarged images show representative results. g Fluorescence intensity of REC8 on centromeric arms (C axes) and acentric arms (A axes) in (f) was measured, respectively. Three independent replicates were performed. h MI stage oocytes microinjected with TRIM21 + IgG or TRIM21 + anti-DRP1 were stained for SMC3 (red). Enlarged images show representative results. i Fluorescence intensity of SMC3 on centromeric arms (C axes) and acentric arms (A axes) in (h) was measured, respectively. Three independent replicates were performed. Chromosomes were stained with Hoechst 33342 (blue), and kinetochores were marked with CREST (magenta in a, d, and green in f, h). Data are presented as the mean ± standard deviation (S.D.). P values were calculated based on nonparametric Kruskal–Wallis tests for (b, e), and unpaired Student’s t test (two-tailed) for (c). Black arrows in (g, i) show the measurement direction. n in graphs refers to the number of oocytes in (b, e), kinetochores in (c) and chromosomes in (g, i), respectively. The white dotted frames in (a, d, f and h) indicate the region shown in detail. Scale bar, 5 μm. NEBD, nuclear envelope breakdown; MI, metaphase I; MII, metaphase II. Representative stainings from at least three independent repeats are shown. Source data are provided as a Source Data file.