In an attempt to examine genomic function of the oocyte nucleus during meiotic maturation, the effects of X-irradiation on the oocyte of the frog (Rana pipiens) were studied. When oocytes were irradiated with 6000-36000 R before initiation of maturation, the ovulated eggs frequently failed to be fertilized and the jelly surrounding the unfertilizable eggs was always damaged. However, the egg it...

In an attempt to examine genomic function of the oocyte nucleus during meiotic maturation, the effects of X-irradiation on the oocyte of the frog (Rana pipiens) were studied. When oocytes were irradiated with 6000-36000 R before initiation of maturation, the ovulated eggs frequently failed to be fertilized and the jelly surrounding the unfertilizable eggs was always damaged. However, the egg it...

BACKGROUND Polycystic ovary syndrome (PCOS) is the commonest cause of anovulatory infertility and menstrual cycle abnormalities, but the factors responsible for failure to select a dominant follicle remain unclear. METHOD Source is authors' own studies and search of the relevant literature. RESULTS Arrest of antral follicle growth is associated with an abnormal endocrine environment involvi...

introduction: the frequency of sperm pcc indiction in normal and infertile men was investigated. material and methods: zona – free hamster oocyte were retrieved after super ovulation by pmsg and hcg infection. following treatment with hyaloronidase, zona was removed by trypsin digestion. sperms were classified with sperms, and then transferred to fresh media containing colcemid. slides were pre...

Background: Intracytoplasmic sperm injection (ICSI) is the choice option for treatment of couples with severe male infertility. Recent studies indicate that the ICSI procedure or the technique itself cannot increase chromosomal abnormalities observed in born children. It maybe result of the Materialss used during ICSI procedure such as PVP and hyalorunidase. Activation of the oocytes might be c...

Background: In vitro maturation (IVM) is a promising treatment option for certain infertile women. Nowadays, with the aid of the Polscope, it has become possible to evaluate zona pellucida (ZP) and spindle as parameters of oocyte quality. The goal was to investigate the relationship between the presence of the meiotic spindle and ZP birefringence with morphology of the in vivo and in vitro matu...

Casein kinase I alpha (CK1α) is a member of serine/threonine protein kinase, generally present in all eukaryotes. In mammals, CK1α regulates the transition from interphase to metaphase in mitosis. However, little is known about its role in meiosis. Here we examined Ck1α mRNA and protein expression, as well as its subcellular localization in mouse oocytes from germinal vesicle to the late 1-cell...

Changes occurring as the prophase I oocyte matures to metaphase II are critical for the acquisition of competence for normal egg activation and early embryogenesis. A prophase I oocyte cannot respond to a fertilizing sperm as a metaphase II egg does, including the ability to prevent polyspermic fertilization. Studies here demonstrate that the competence for the membrane block to polyspermy is d...

The quality of sperm DNA is very important in maintaining the reproductive potential of men. Sperm DNA is resistant to many types of insults that occur during its journey from the testis to time it reaches the oocyte for fertilization. During natural conception, a selection process occurs that allows only sperm with intact DNA to fertilize an oocyte. When assisted reproductive techniques (ART) ...