The mechanisms and aetiology underlying the development of premature ovarian insufficiency (POI) are poorly understood. However, oocyte clearly has a role as demonstrated by Double Mutant (DM) mouse model where dysfunction (6 weeks) is followed POI (3 months) due to oocyte-specific deletion complex hybrid N- O-glycans. ovaries DM mice contain more primary follicles (3a stage) accompanied fewer ...

the purpose of this study was to evaluate the efficiency of intracytoplasmic sperm injection (icsi) and piezo-assisted sperm injection after pretreatment with calcium ionophore (cai) on the mouse embryo development. methods: in this study, the conventional icsi and piezo-icsi procedures were used. the efficacy of the methods was examined after mouse matured oocytes were fertilized with or witho...

background: ovarian tissue transplantation is emerging technologies for fertility preservation. in addition, in vitro maturation (ivm) of oocytes retrieved from ovarian tissues may overcome the fertility defects in certain cases. objective: the aim was to evaluate the best site for ovarian tissue transplantation in mice. also, feasibility of ivm of oocytes retrieved from auto grafted ovarian ti...

Here, we report the recovery of cell nuclei from 14,000-15,000 years old mammoth tissues and the injection of those nuclei into mouse enucleated matured oocytes by somatic cell nuclear transfer (SCNT). From both skin and muscle tissues, cell nucleus-like structures were successfully recovered. Those nuclei were then injected into enucleated oocytes and more than half of the oocytes were able to...

Phorbol ester (PMA) in concentration 5 and 10 ng ml-1 blocks cytokinesis of the second maturation division in mouse oocytes. Karyokinesis is not impaired and digynic triploid oocytes are obtained which undergo first cleavage division. Effectiveness of blocking cytokinesis is dependent on the timing of exposure of oocytes to PMA action. When oocytes are subjected to PMA at the onset of the secon...

High resolution two-dimensional electrophoresis has been used to examine the pattern of protein synthesis during meiotic maturation of mouse oocytes in vitro. Fluorograms of [35S]methionine-labeled oocyte proteins have revealed that meiotic progression from dictyate to metaphase II (meiotic maturation) is accompanied by marked changes in the pattern of proteins synthesized by oocytes. Virtually...

Thioredoxin-interacting protein (Txnip) regulates intracellular redox state and prompts oxidative stress by binding to and inhibiting Thioredoxin (Trx). In addition, via a Trx-independent mechanism, Txnip regulates glucose metabolism and thus maintains intracellular glucose levels. Previously, we found Txnip mRNA highly expressed in immature germinal vesicle (GV) oocytes, but currently there is...

In mammals, unfertilized oocytes are one of the most available stages for cryopreservation because the cryopreserved oocytes can be used for assisted reproductive technologies, including in vitro fertilization (IVF) and intracytoplasmic sperm injection. However, it has generally been reported that the fertility and developmental ability of the oocytes are reduced by cryopreservation. C57BL/6J m...

It has been suggested that germline stem cells maintain oogenesis in postnatal mouse ovaries. Here we show that adult mouse ovaries rapidly generate hundreds of oocytes, despite a small premeiotic germ cell pool. In considering the possibility of an extragonadal source of germ cells, we show expression of germline markers in bone marrow (BM). Further, BM transplantation restores oocyte producti...

Conventionally, intracytoplasmic sperm injection (ICSI) in the mouse is conducted with piezo-drills that use a droplet of mercury for damping. The use of mercury causes concerns of toxicity and contamination. Although Fluorinert can be used as a substitute for mercury to reduce piezo-drill’s lateral vibration, the damping effect is not as satisfactory as mercury. In this work, a modified piezo-...