Combinations of progesterone, lutenizing hormone releasing hormone analogue (LHRHa), human chorionic gonadotrophin (hCG), and the dopamine-2 (DA2) receptor antagonist 1-[1-[4,4-bis(4-Fluorophenyl)butyl]-4-piperidinyl]-1,3-dihydro-2H-benzimidazol-2-one (Pimozide; Orap) were tested for improvement of spawning rates, oocyte numbers, fertilization and neurulation rates of the Fowler toad (Bufo fowl...

Knowledge about the mechanism that establishes embryonic polarity is fundamental in understanding mammalian development. In re-addressing several controversial claims, we recently proposed a model in which mouse embryonic polarity is not specified until the blastocyst stage. Before fertilization, the fully differentiated oocyte has been characterized as "polarized," and we indeed observed that ...

In recent years, the biochip by MEMS technology has been developed. The biochip has the advantages of biocompatibility, precision, low-cost, disposable, and easy to produce etc. MEMS technology widely used in cell detection or position a single-cell level, including the mechanical, optical electromagnetic and electronic fields. This study proposal, imitate the oviduct that can effectively posit...

BACKGROUND The enzyme hyaluronidase from bovine origin is commonly used for oocyte-cumulus cell removal in ICSI. A recombinant human hyaluronidase (rHuPH20) has been introduced as a quality-controlled and safe alternative. METHODS In order to validate its effectiveness, a non-inferiority trial was started on sibling cumulus-oocyte complexes (135 ICSI patients). Oocyte denudation involved enzy...

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...

Ca(2+) is the universal signal for egg activation at fertilization in all sexually reproducing species. The Ca(2+) signal at fertilization is necessary for egg activation and exhibits specialized spatial and temporal dynamics. Eggs acquire the ability to produce the fertilization-specific Ca(2+) signal during oocyte maturation. However, the mechanisms regulating Ca(2+) signaling differentiation...

Increased glucocorticoid levels, due to medical therapy or stress-related, may affect reproduction via the hypothalamus-pituitary-axis or directly at the oocyte level. We examined the effects of natural (corticosterone) or synthetic (dexamethasone) glucocorticoids on mouse oocyte maturation and underlying changes in extracellular signal-regulated kinase (ERK) phosphorylation patterns. Fertiliza...

background & objectives : different energy substrates and nutrients can greatly influence oocyte nuclear and cytoplasmic maturation. effect of glucose on in-vitro oocyte maturation and subsequent early embryonic development is controversial. the objective of the present study was to verify the effect of various concentrations of glucose on cumulus-oocyte complexes maturation, fertilization and ...

Oocyte maturation is known to affect the chances for successful fertilization, embryonic development, establishment of pregnancy and delivery of a live, healthy, and viable offspring. Two-photon laser scanning microscopy (TPLSM) has previously been used to evaluate early embryonic development without a detectable impairment of subsequent development, but has never been applied to assess mammali...

Complete functional oocyte maturation involves many complex processes that occur within preovulatory follicles and are initiated and sustained by the gonadotropins, steroid hormones and many recognized and unrecognized factors. The product of oocyte maturation is a mature egg that has complete nuclear, plasma membrane and cytoplasmic changes that enable normal fertilization and subsequent devel...