Background: Cryopreservation of farm animal embryos is nowadays a widely used routine technique. Success in cryopreservation of form animal depends on many factors including: freezing medium, types of cryoproctants, melting process, lipid content in ooplasm and oocyte quality It has been found that immature Oocytes with reduced reproductive performance or slaughtered at the end of their use are...

BACKGROUND The efficiency of in vitro maturation (IVM) techniques is suboptimal compared with controlled ovarian stimulation combined with IVF cycles, and studies are needed to identify factors that predispose IVM cycles to success or failure. We compared the outcome of IVM cycles with different dominant follicle (DF) size at oocyte retrieval following hCG priming. METHODS IVM was performed i...

This paper deals with the relationship between the single copy transcripts represented in mature oocytes of the sea urchin and the RNA sequences present in immature oocytes and embryos. We term the oocyte transcripts from single copy DNA the maternal single copy sequence set. A single copy VHIDNA fraction VHloDNA) enriched for sequences complementary to the maternal single copy sequence set was...

background: artificial stimulation of mouse oocyte, in the absence of sperm contribution, can induce its parthenogenic activation of oocyte. ultrasound is one of the newest methods for artificial activation of mammal oocytes, and its successful utilization in pig oocyte activation has been recently reported. our objective was to assess the effect of ultrasound on mouse oocyte activation. materi...

The relationship between onset of the early cytoplasmic stages of oocyte activation (vitelline membrane separation and elevation) and nuclear meiotic maturation was investigated in starfish oocytes after their exposure to divalent ionophore (A-23187) or sperm. Meiotically mature oocytes, isolated in calcium-free seawater, underwent activation in response to sperm or ionophore as previously repo...

Maintaining and restore the full developmental competence of either mature or immature oocytes after cryopreservation processes to preserve women fertility is a goal in assisted reproductive technologies (ART). This goal arises from the need of some patients to preserve their oocytes before arriving to a reproductively mature age, such as patients who need to undergo chemotherapy. Although in v...

OBJECTIVE The aim of this study was to report a case series of in vitro matured (IVM) oocyte freezing in gynecologic cancer patients undergoing radical surgery under time constraints as an option for fertility preservation (FP). METHODS Case series report. University-based in vitro fertilization center. Six gynecologic cancer patients who were scheduled to undergo radical surgery the next day...

It has been suggested that nucleus replacement (transfer) may be used as an efficient oocyte therapy in order to prevent transmission of mutated mitochondrial DNA from mother to offspring in humans. The essential and not yet answered question is how mitochondria surrounding the karyoplast will be distributed in the newly reconstructed oocytes. In our model experiments, we have evaluated the dis...

Abstract Compared to somatic or sperm cells, mammalian oocytes are much more sensitive cryopreservation mainly because of the large volume, cytoskeleton, and presence zona pellucida. Connections with surrounding cumulus cells also challenging preserve in immature oocytes. Besides genetic epigenetic information enclosed nucleus, contain organelles cytoplasmic factors that necessary for early emb...

OBJECTIVE To investigate the effect of a phosphodiesterase type 3 inhibitor in oocyte maturation medium on subsequent embryo development. DESIGN Animal study. SETTING University laboratory. ANIMAL(S) CD-1 mice. INTERVENTION(S) Immature oocytes were arrested meiotically in medium containing a specific phosphodiesterase type 3 inhibitor, cilostamide (1 micromol/L, 5 micromol/L, and 10 mic...