The physiological trigger for meiotic resumption in the human oocyte is the surge of luteinizing hormone, but it can also occur spontaneously if oocytes are released from antral follicles and cultured in vitro. The development of novel techniques for the culture of murine oocytes has raised the possibility of growing human oocytes to maturity in vitro. Such a system could open the door to a num...

INTRODUCTION In women showing impaired fertility, a decreased response to ovarian stimulation is a major problem, limiting the number of oocytes to be used for assisted reproduction techniques (ART). Despite the several definitions of poor response, it is still a matter of debate whether young poor responder patients also show a decrease in oocyte quality. The objective in this study was to inv...

During first gamete interaction, oligosaccharides on the glycoproteins present in oocyte envelopes of the rock shrimp, Rhynchocinetes typus, play an important role in spermatozoon recognition prior to the onset of penetration. These oligosaccharides have terminal monosaccharides that may be recognized by means of specific lectins. A variety of marine species have monosaccharides on their oocyte...

If fertilization of matured oocyte does not occur, unfertilized oocyte undergoes aging, resulting in a time-dependent reduction of the oocyte's quality. The aging of porcine oocytes can lead to apoptosis. Carbon monoxide (CO), a signal molecule produced by the heme oxygenase (HO), possesses cytoprotective and anti-apoptotic effects that have been described in somatic cells. However, the effects...

2. The biology of the oocyte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214 2.1. Oogenesis and development . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214 2.2. Bioelectrical properties of the oocyte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215 2.3. The oocyte at work...

The aim of this study was to investigate the effects of iron and copper on bovine oocyte maturation, preimplantation embryo development and apoptosis of blastocysts. The concentrations of iron in the culture media were 0 (control), 0.45, 0.81, 1.96 and 3.26 mg/l, and the concentrations of copper were 0 (control), 0.093, 0.27, 0.46 and 0.68 mg/l. The changes in the iron (1.96 mg/l) and copper co...

introduction: genital system is important herd in animal's creation. it is necessary for animal reproduction. mammal has two sex in genital system such as male and female in separated animals. animal reproduction destroyed by disorder of genital system. in this case, animals cannot produce an animal similar to them. finally it cause overthrow a species of animals. methods: histomorphologic...

Background: Polycystic ovary syndrome (PCOS) is a frustrating experience for women, considered as a complex challenge for researchers and clinicians. Despite the enormous effort to define the cause of PCOS, the etiology and pathogenesis still remain unclear. Oocyte quality is reflected in the oocyte’s intrinsic developmental potential. Studies have shown that the follicular development is disru...