The in vitro matured OLCs presented the polar body and arrested at metaphase II (MII) stage. Some OLCs were self-activated and spontaneously developed into multiple-cell structures similar to preimplantation embryos, indicating that OLCs were parthenogenetically activated though in vitro fertilization ...
Oocytes obtained during in vitro fertilization (IVF) cycles ideally are arrested in metaphase II (MII), which are characterized by the presence of a single polar body. They remain in arrest until after fertilization when time meiosis is resumed in a calcium-dependent manner. We present a case ...
The meiotic cell cycle proceeds immediately to metaphase of meiosis II and then becomes arrested at this stage; the oocyte is now referred to as a secondary oocyte or metaphase II–arrested egg (Fig. 9.17). Arrest in metaphase II occurs before physical release of the egg from the follicle ...
After ovulation, the human oocyte is arrested at the metaphase of meiosis II (MII). When the sperm fuses with the oocyte, the oocyte is activated, meiosis resumes, and half of the sister chromatids are extruded into a second polar body7. The fertilised oocyte enters interphase before starting...
We found that most control oocytes were arrested in the anaphase/telophase I (ATI) and metaphase II (MII) stages, whereas most NaF-treated oocytes were arrested in the GVBD and metaphase I (MI) stages (Fig. 3b,c). Higher percentage of control oocytes were in the ATI/MII stage than ...
Maro B, Howlett SK, Webb M. Non-spindle microtubule organizing centers in metaphase II-arrested mouse oocytes. J Cell Biol. 1985;101:1665–72. Article Calarco-Gillam PD, Siebert MC, Hubble R, Mitchison T, Kirschner M. Centrosome development in early mouse embryos as defined by an autoantibod...
(1) Oocyte Enucleation: Mature metaphase II (MII) oocytes are transiently exposed to UV light to aspirate the MII plate. (2) Somatic cell fusion: An enucleated oocyte is combined with a donor cell (eg, a fibroblast) nucleus through a precise fusion process. (3) Artificial Activation: The ...
in the somatic layers of the ovarian follicle in mouse and cow species during oocyte developmental competence acquisition: developmentally incompetent or poorly competent prophase I oocytes (NC1), developmentally competent prophase I oocytes (C1), and developmentally competent metaphase II oocytes (C2). ...
The morphologic classification of MII generally denotes an oocyte that is “mature,” having arrested in metaphase II and is presumed to be capable of fertilization. However, there are subsets of women who produce oocytes with MII morphology that are not capable of embryo formation even with ferti...
Moreover, the second polar body (PB) and the pseudopolar body (PPB) were excluded from the spindle-chromosome complex and the donor metaphase nucleus, respectively, resulting in a reconstructed embryo containing diploid DNA. Injected oocytes developed into blastocysts at a rate of 51% (Figure 4C...