Miscellaneous spindle assembly modes around proximate parental genomes in live bovine zygotes. (A–E) Bovine zygotes expressing microtubule markers (EGFP-MAP4 in A–D or EB3-mEGFP2 in E, green) and chromatin marker (H2B-mCherry, magenta) were imaged by light-sheet microscopy every 2.5 min throughout mitosis and for up to 6 h in total. 3D-rendered images of pronuclear volumes after background correction (median-based denoising) show examples of spindle formation and dynamics from prophase to metaphase. Indicated timings respective to synchronous pro-NEBD or to NEBD of first PN (PN1) in case of asynchrony. PN2, lagging PN. Arrowheads indicate positions of centrosomes. Projected scale bars, 10 µm. (A–C) Spindle assembly modes around adjacent PNi, where centrosomes localized at PN surfaces, but not at the PN interphase junctions (n = 4). Centrosomes either localized in proximity to each other, but not perfectly at PN interphase (A and B) or at opposite sides of same PN, with only one centrosome at PN interphase (C). (D and E) Spindle assembly around adjacent PNi, where only one centrosome localized to PN surface/interphase and the second was randomly positioned in cytoplasm without clear nuclear attachment (n = 3).