introduction: the purpose of this study was to investigate the effect of vitrification procedure on the survival, fertilization, development and ultrastructure of metaphase (mii) mouse oocyte. materials and methods: female nmri mice 6-10 weeks old were superovulated using ip injection of 10 iu hmg and 10 iu hcg. ovulated oocyte were collected from the ampullary portion of the oviducts at 12-13 ...

Primary spermatocytes are the male germ cells before meiosis I. To examine whether these 4n diploid cells are genetically competent to fertilize oocytes and support full embryo development, we introduced the nuclei of pachytene/diplotene spermatocytes into oocytes that were arrested in prophase I (germinal vesicle stage), metaphase I, or metaphase II (Met II). Both the paternal and maternal chr...

Abstract Study question Whether high proportion of immature oocyte in a cohort impacts outcome sibling mature ICSI cycles. Summary answer demonstrate that if retrieved was more than 50% cycle then it reduces reproductive with the remaining oocytes. What is known already The selection competent crucial to assisted technique procedure outcome. In where only metaphase II oocytes (MII) are injected...

Cep55 is a relatively novel member of the centrosomal protein family. Here, we show that Cep55 is expressed in mouse oocytes from the germinal vesicle (GV) to metaphase II (MII) stages. Immuostaining and confocal microscopy as well as time lapse live imaging after injection of mRNA encoding fusion protein of Cep55 and GFP identified that Cep55 was localized to the meiotic spindle, especially to...

In order to achieve developmental competence, porcine oocytes must undergo both nuclear and cytoplasmic maturation. Nuclear maturation results from breakdown of the germinal vesicle (GV) and progression of meiosis to metaphase II (MII). Cytoplasmic maturation is the accumulation, within the oocyte’s cytoplasm, of products necessary for fertilization, cleavage and development, prior to activatio...

Mouse oocytes were placed in Hepes-T6 containing 7.5 μg/ml cytochalasin B and 5μg/ml Hoechst prior to enucleation, and enucleation was performed on oocytes using the manipulator. The oocyte held in place by gentle suction of a holding pipette (oocyte diameter approx.70 μm). The metaphase spindle (arrow) is aspirated into an enucleation pipette (1).

The dynamics of the Aurora B protein kinase during Xenopus oocyte meiotic maturation were examined. Resting G2 oocytes express inactive Aurora B that is not associated with other subunits of the chromosome passenger complex (CPC). Activity increases near the time of germinal vesicle breakdown in progesterone-treated oocytes, and this increase is correlated with the synthesis of inner centromere...

Improved methods are needed to reliably and accurately evaluate oocyte quality prior to fertilization and transfer into the woman of human embryos created through in vitro fertilization (IVF). All oocytes that are retrieved and matured in culture are exposed to sperm with little in the way of evaluating the oocyte quality. Furthermore, embryos created through IVF are currently evaluated for dev...