Correlation of abnormal mitochondrial distribution in mouse oocytes with reduced developmental competence.

Selection of good quality oocytes is important for improvement of assisted reproductive technology. Here, we studied the relationship of the mitochondrial distribution in metaphase II stage (MII) oocytes with fertility, since mitochondria in ooplasm are essential for energy production required for fertilization and embryo development. To observe mitochondria non-invasively, we used oocytes from a transgenic mouse, in which enhanced green fluorescent protein is targeted to the mitochondrial matrix and thus fluorescence is observed exclusively in the mitochondria.

Oocyte mitochondria: strategies to improve embryogenesis.

Mitochondria play a central role to provide ATP for fertilization and preimplantation embryo development in the ooplasm. The mitochondrial dysfunction of oocyte has been proposed as one of the causes of high levels of developmental retardation and arrest that occur in preimplantation embryos generated using Assisted Reproductive Technology. Cytoplasmic transfer (CT) from a donor to a recipient oocyte has been applied to infertility due to dysfunctional ooplasm, with resulting pregnancies and births.

Effect of repeated administration of clomiphene citrate at two different times on the endometrium in patients undergoing intrauterine insemination.

Clomiphene citrate (CC) has been widely used for induction of ovulation; however, despite the high rate of ovulation, the pregnancy rate is only 30%. The anti-estrogenic effect of CC on the endometrium is one explanation for this finding. It is well known that repeated administration of CC enhances its anti-estrogenic effect.

Cytoplasmic transfer in the mouse in conjunction with intracytoplasmic sperm injection.

Cytoplasmic transfer (CT) from a donor to a recipient oocyte has been used clinically to facilitate human pregnancies. Data reported here describe the first characterization of CT coincident with intracytoplasmic sperm injection in the mouse system. Sibling oocytes were used to transfer 2, 4, or 6 pl of ooplasm to a recipient egg along with a sperm head using piezo-actuated injection.

Oxidative state and zona-binding ability in mouse spermatozoa treated with reduced glutathione.

Nuclear proteins in mature mammalian spermatozoa nuclei are oxidized to form numerous disulfide bonds. Reduced glutathione (GSH) in the oocyte has been linked to spermatozoan nuclear decondensation after fertilization. In this study, we analyzed whether GSH reduced protamines in sperm nuclei , and examined the zona-binding ability of treated nuclei.

Relationship between sperm mitochondrial membrane potential, sperm motility, and fertility potential.

Aim: To analyze the relationship between sperm mitochondrial membrane potential and sperm motility parameters by means of a computer-assisted sperm analyzer (CASA) and in-vitro fertilization rate(%FR).

Methods: Semen samples were obtained from 26 men undergoing in vitro fertilization-embryo transfer (IVF-ET). Informed consent was obtained from all men prior to the study.