Mature mammalian oocytes undergo a prolonged series of cytoplasmic calcium (Ca(2+)) oscillations at fertilization that are the cause of oocyte activation. The Ca(2+) oscillations in mammalian oocytes are driven via inositol 1,4,5-trisphosphate (IP3) generation. Microinjection of the sperm-derived phospholipase C-zeta (PLCζ), which generates IP3, causes the same pattern of Ca(2+) oscillations as...

OBJECTIVES The aim of this study was to evaluate the fetal mouse lung tissue co-culture on in vitro maturation (IVM) of mouse immature oocytes. MATERIALS AND METHODS In this experimental study, germinal vesicle (GV) oocytes from ovaries of a group of 25 female mice, 6-8 weeks of age, were dissected after being stimulated by 7.5 IU pregnant mare serum gonadotropin (PMSG) through an intraperito...

Hyaluronidase is generally used to remove cumulus cells from mouse oocytes before oocyte cryopreservation, intracytoplasmic sperm injection or DNA injection. In general, use of cumulus-free mouse oocytes decreases in vitro fertilizing ability compared with cumulus-surrounded oocytes. The effect of hyaluronidase exposure on the quality of mouse oocytes is not fully understood. Here, we investiga...

Background: Polycystic ovary syndrome (PCOS) is characterized by chronic anovulation and hyperandro genism and affects approximately 5-10% of women of reproductive age. In vitro maturation (IVM) of mammalian oocytes has become an efficient method to produce mature oocytes in order to use in assisted reproductive techniques such as in vitro fertilization (IVF), intra cytoplasmic sperm injection ...

background: the objective of this study was to investigate the effect of vitrification and in vitro maturation on the mitochondrial distribution and atp content of oocytes. methods: the oocytes at germinal vesicle (gv) and metaphase ii (mii) stages were recovered from 6-8 week old nmri strain female mice. the oocytes were divided into vitrified and non-vitrified groups. vitrification was done b...

BACKGROUND The ovulatory gonadotropin surge increases synthesis of prostaglandin E2 (PGE2) by the periovulatory follicle. PGE2 actions on granulosa cells are essential for successful ovulation. The aim of the present study is to determine if PGE2 also acts directly at the oocyte to regulate periovulatory events. METHODS Oocytes were obtained from monkeys and mice after ovarian follicular stim...

Background and aims: Phthalates, which are commonly used to render plastics into soft and flexible materials, have also determined as developmental and reproductive toxicants in human and animals. The purpose of this study was to evaluate the effect of mono-(2-ethylhexyl) phthalate (MEHP) and di-(2-ethylhexyl) phthalate (DEHP) oral administration on maturation of mouse oocytes, apoptosis and ge...

Effective protocols are introduced for parthenogenesis activation in oocytes. Hydrostatic pressure can act as a mechanical stimulator that rearranges egg contents, leading to new structural or molecular combination. Alternatively, mechanical stimulation could stimulate a mechanically-gated process, such as opening or closing of stretch activated ion channels. This study, investigated the use of...

Background: The purpose of this research programme is to improve understanding of the molecular and cellular processes that lead to selection of oocytes before birth. Vastly more oocytes are produced prenatally than can be utilised in reproductive life. Around 70%, of oocytes formed are eliminated before birth and never contribute to the ovarian reserve. After birth, the number of oocytes conti...

Aneuploidy tests are important in evaluating genetic hazards especially when chemical exposures are suspected to affect the fidelity of chromosome segregation in oocytes and embryos. In the current study, a newly established method, mouse preantral follicle culture, was employed to grow oocytes in vitro within follicles. The sensitivity of in vitro grown follicle enclosed oocytes was compared w...