Frog eggs are normally fertilized after reaching metaphase II. When eggs are inseminated prior to that, several sperm enter, but entry does not activate the egg. When such inseminated, immature eggs were maintained until they became mature and then were artificially activated, the eggs began to cleave. The cleavage furrows were irregular and often multiple, but the eggs developed to blastulae o...

A study was made of the electrical and morphological changes in the sea-urchin oocyte during interaction with spermatozoa. The first event, a small step depolarization accompanied by a 20-40% decay in input resistance occurs within seconds of attachment. The evidence suggests that this electrical event is the result of sperm-oocyte fusion, and that the ion channels that lower the resistance acr...

The intracytoplasmic sperm injection (ICSI) procedure has recently been utilized to produce transgenic animals and may serve as an alternative to the conventional pronuclear microinjection in species such as pigs whose ooplasm is opaque and pronuclei are often invisible. In this study, the effects of sperm membrane disruption and electrical activation of oocytes on in vitro development and expr...

Fertilisation by intracytoplasmic sperm injection (ICSI), a technique that bypasses the membrane fusion of the gametes, has been widely used to produce offspring in humans and mice. Success with this technique has lent support to the hypothesis that in mammalian fertilisation, a factor from the sperm, the so-called sperm factor, is responsible for oocyte activation and that the fusion process i...

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...

Artificial oocyte activation to overcome failed fertilization after intracytoplasmic sperm injection (ICSI) in human oocytes typically employs Ca2+ ionophores to produce a single cytosolic Ca2+ increase. In contrast, recombinant phospholipase Czeta (PLCz) causes Ca2+ oscillations indistinguishable from thoseoccurring during fertilization, but remains untested for its efficacy in a scenario of I...

Artificial oocyte activation to overcome failed fertilization after intracytoplasmic sperm injection (ICSI) in human oocytes typically employs Ca(2+) ionophores to produce a single cytosolic Ca(2+) increase. In contrast, recombinant phospholipase Czeta (PLCζ) causes Ca(2+) oscillations indistinguishable from those occurring during fertilization, but remains untested for its efficacy in a scenar...

interaction effect of three level of male age broodstock and three type of diluents (distilled water and diluents 1 and 2) for duration of motility and eyed egg rate in rainbow trout (oncorhynchus mykiss) have been studied. there was no significant difference in activation of sperm by control group (distilled water) in different male ages (p?0.05). diluents 1, in 3+ year male broodstock has sho...

Factors that affect sperm quality can include method of semen collection, conditions for capacitation and whether or not agglutination is present. Media and procedures for sperm washing can also impair or improve sperm function in assisted reproductive technologies. For example, the removal of seminal fluid through large volume washing is required to eliminate decapacitation activity of seminal...

ZP3 is a protein in the mammalian egg coat (zona pellucida) that binds sperm and stimulates acrosomal exocytosis, enabling sperm to penetrate the zona pellucida. The nature of the ZP3 receptor/s on sperm is a matter of considerable debate, but most evidence suggests that ZP3 binds to beta-1,4-galactosyltransferase-I (GalTase) on the sperm surface. It has been suggested that ZP3 induces the acro...