Bovine parthenotes cluster chromosomes toward the midbody of the meiosis II spindle, related to Figure 4
(A) Representative stills from time-lapse movies of bovine parthenotes with 2 pronuclei. White, microtubules (mClover3-MAP4-MTBD). Magenta, DNA (H2B-mScarlet). Time, h:m, 00:00 is NEBD. Z-projections, 15 sections every 2.50 μm.
(B-C) Max chromatin polarity and inner chromatin fraction indices before NEBD in zygotes (same as Figure S2E) and parthenotes.
(D) Representative stills from time-lapse movies of parthenotes with 2 pronuclei. Green, NPC (bElys-mClover3). White, microtubules (mScarlet-MAP4-MTBD). Magenta, DNA (H2B-miRFP). Arrows point to the meiosis II microtubule spindle that becomes a midbody and acts as microtubule organizing center, persisting for long after the end of meiosis. In the top row, the microtubule signal bleeds into the DNA channel. The midbody is thus also visible in magenta. Time, h:min, 00:00 is egg activation. Z-projections, 3 (first three frames) and 2 (last two frames) non-consecutive sections to display both pronuclei.
(E) Parthenotes with or without a midbody acting as microtubule organizing center (MTOC) at the onset of pronuclear expansion.
(F) Parthenotes with or without a polarized distribution of Elys during pronuclear expansion.
(G) Parthenotes with or without a polarized distribution of Elys during pronuclear expansion in the presence or absence of a midbody MTOC.
(H) Zygotes and parthenotes having one or two spindles after NEBD. Zygotes are those in the clustered and unclustered categories from Figure 3B.
(I) Parthenotes with two spindles after NEBD were scored for spindle merging before anaphase onset.
(J) Zygotes and parthenotes in indicated groups having abnormal mitosis. Zygotes are the same analyzed in Figure 4K.
Data are from four (parthenotes groups in B, C, H, J, and E, F, G, I) and eleven (zygote groups in B, C, H, J) independent experiments. The number of analyzed pronuclei (B, C), parthenotes (E, F, G, H, I, J), and zygotes (H, J) are specified in italics. p values were calculated using unpaired two-tailed Student’s t test (B, C) and Fisher’s exact test (G, H, J). Scale bars, 10 μm.