Fig. 5: DRP1 loss leads to premature degradation of cyclinB1 and Securin.

a Premature degradation of cyclinB1 and Securin after DRP1 depletion in oocytes prior to MI stage. Per lysate contains 100 oocytes (NEBD + 6 h). β-Tubulin was used as the loading control. b, c Accumulation of cyclinB1 and Securin after DRP1 overexpression in GV stage (b) or pro-MI stage (c) oocytes. Per lysate contains 100 oocytes (NEBD + 7.5 h). β-Tubulin was used as the loading control. d, e Live-cell imaging of eGFP-cyclinB1 (d) and mCherry-Securin (e) in control or DRP1 null oocytes. Control and DRP1 null oocytes were injected with eGFP-cyclinB1 or mCherry-Securin mRNA, respectively. See also in Supplementary Movie 1–4. f, g Time-lapse fluorescence intensities of eGFP-cyclinB1 in (d) and mCherry-Securin in (e) were measured, respectively. Three independent replicates were performed. h, i Live-cell imaging of eGFP-cyclinB1 (h) and mCherry-Securin (i) in control or DRP1 overexpressed oocytes. Control and DRP1 overexpressed oocytes were injected with eGFP-cyclinB1 and mCherry-Securin mRNA, respectively. See also in Supplementary Movie 5–8. j, k Time-lapse fluorescence intensities of eGFP-cyclinB1 in (h) and mCherry-Securin in (i) were measured, respectively. Three independent replicates were performed. l, m Live-cell imaging of eGFP-cyclinB1 (l) and mCherry-Securin (m) in control or DRP1 null oocytes cultured with nocodazole. Oocytes were injected with eGFP-cyclinB1 or mCherry-Securin mRNA, and incubated in the medium containing milrinone for 2 h. Then the oocytes were released from milrinone for further maturation in the medium containing nocodazole. See also in Supplementary Movie 9–12. n, o Time-lapse fluorescence intensities of eGFP-cyclinB1 in (l) and mCherry-Securin in (m) were measured, respectively. Three independent replicates were performed. Time points after NEBD are indicated as hours: minutes in (d, e, h, i, l and m). Data are presented as the mean ± standard deviation (S.D.). n in graphs (f, g, j, k, n and o) refers to the total number of oocytes. Scale bar, 20 μm. NEBD, nuclear envelope breakdown; MI, metaphase I. Representative blots or captures from at least three independent repeats are shown. Source data are provided as a Source Data file. See also in Supplementary Fig. 8.