BACKGROUND The purpose of this study was to investigate the chromosomal complement and developmental potential of in-vitro matured murine oocytes following ICSI by human sperm. METHODS Heterologous ICSI fertilization between mouse oocytes and human sperm was employed in order to overcome the reduced fertilization rates observed after conventional IVF due to zona hardening during in-vitro matu...

Estimates of genetic risks from radiation delivered to humans are derived largely from mouse studies. In males, the target is spermatogonia and a large amount of information is available. In contrast, in females, immature oocytes are the target, but extrapolations from mice to humans are not very definitive because immature mouse oocytes are highly sensitive to radiation and die by apoptosis, w...

OBJECTIVE The aims of this study were to investigate whether fertilization could induce the resumption of meiosis in mouse oocytes arrested at metaphase I (MI) after in vitro maturation (IVM), and to investigate the effect of Ca2+ chelator treatment at the time of fertilization on the transition from MI to metaphase II (MII). METHODS MII-stage and arrested MI-stage mouse oocytes after IVM wer...

In oocytes, asymmetric cytokinesis represents a conserved strategy for karyokinesis during meiosis to retain ooplasmic maternal factors needed after fertilization. Given the role of gamma-tubulin in cell cycle progression and microtubule dynamics, this study focused on gamma-tubulin as a key regulator of asymmetric cytokinesis in mouse oocytes. Gamma-tubulin properties were studied using multip...

BACKGROUND To better understand the differences between in vivo (IVO) and in vitro (IVM) matured oocytes, we studied the chronological changes in cortical granule (CG) distribution and nuclear progression during maturation, and the competence of CG release and embryo development of mouse oocytes matured under different conditions. METHODS Oocytes matured in vivo or in different culture media ...

Mouse oocytes undergo two successive meiotic divisions to generate one large egg with two small polar bodies. The divisions are essential for preserving the maternal resources to support embryonic development. Although previous studies have shown that some small guanosine triphosphatases, such as RAC, RAN, and CDC42, play important roles in cortical polarization and spindle pole anchoring, no o...

BACKGROUND Type I diabetes is a global public health concern that affects young people of reproductive age and can damage oocytes, reducing their maturation rate and blocking embryonic development. Understanding the effects of type I diabetes on oocytes is important to facilitate the maintenance of reproductive capacity in female diabetic patients. METHODS To analyze the effects of type I dia...

The meiotic progression of Xenopus oocytes has been suggested to depend on the activity of cyclin-dependent kinase 2 (Cdk2). We examined whether Cdk2 is involved in the regulation of mammalian oocyte meiosis by injecting porcine oocytes with anti-Cdk2 antibody. At first, the cross-reactivity of the anti-Cdk2 antibody with Cdc2 kinase was evaluated by immunoprecipitation and immunoblotting exper...

Processing bodies (P-bodies) are cytoplasmic granules involved in the storage and degradation of mRNAs. In somatic cells, their formation involves miRNA-mediated mRNA silencing. Many P-body protein components are also found in germ cell granules, such as in mammalian spermatocytes. In fully grown mammalian oocytes, where changes in gene expression depend entirely on translational control, RNA g...

BACKGROUND Germinal vesicle transplantation (GVT) provides a means of investigating interactions between karyoplasts and cytoplasts isolated from different cells. Technically, GVT can be accomplished with a high degree of efficiency without compromising the maturation of either the human or mouse oocyte nucleus. Although maturation, fertilization and preimplantation development have been establ...