Fig. 2. Parthenogenesis follows normal meiotic progression in rPLCZ1-expressing hemizygous female mice. (A) Immunofluorescence microscopy of oocytes matured in vitro at <2 (GV) or 8-10 (mI) hours after meiotic resumption, or 13 hours post-hCG (mII). Oocytes were from hemizygotes (CS) and age-matched non-transgenic littermates (wt). TUBA2 labelling is green and genomic DNA red. Arrows and arrowheads respectively mark the first polar body (Pb₁) and mII plate. (B) Proportion of age-matched oocytes upon collection at mII 13 (white) and 24 (grey) hours post-hCG. (C) Hofmann image of F₄ oocytes 13.5-14 hours post-hCG, showing metaphase or anaphase-telophase distortions (arrowheads) and Pb₁ (arrows). (D) Immunofluorescence microscopy of different oocytes from C, 14 hours post-hCG, at early (upper) and late (beneath) stages of spindle rotation, represented diagrammatically to the right. Staining and key to arrow and arrowheads are as for A. (E) Ratiometric Fura 2-AM [Ca²⁺]_i imaging of representative oocytes at different stages, performed as for A but with mII oocytes 14.5 hours post-hCG. Oocytes were from non-transgenic control (wt, upper) and age-matched transgenic (CS, beneath) females. (F,G) Hofmann images (F) and bar chart (G) showing development in vitro of CS16 F₃ (CS) and SrCl₂-induced wild-type (wt) haploid parthenogenotes at the times shown after oocyte collection or activation. Pronuclei and Pb₂ in F are respectively indicated with arrowheads and arrows. (H) Preimplantation development following nuclear transfer (nt) from CS16 F₄ cumulus cell nuclei into enucleated wild-type oocytes without exogenous activation, shown at the times indicated (hours) post-nt. Pronuclei are indicated with arrowheads. (I) Developmental rates in vitro following nt of CS16 F₃ and F₄, or age-matched non-transgenic or pCAGmtVenus transgenic (Shoji et al., 2006) cumulus cells (control) into enucleated wild-type oocytes. m/b (in G,I), morula/blastocyst. Scale bars: 20 µm.