Mature bovine oocytes were activated with 7% ethanol followed by cytochalasin B or D treatment. Most oocytes extruded a second polar body and formed one pronucleus when treated with 7% ethanol alone [35/43 (81%)]. With ethanol followed by cytochalasin B or D, overall activation frequency was 70% (309/441), with activated oocytes containing two pronuclei. The cleavage rate was not significantly ...

Background: The parthenogenetic of oocytes is important in cloning research, as artificial activation of oocytes is an essential component of nucleus transfer protocols. Hydrostatic pressure can act as a mechanical stimulator that rearranges egg contents. Ethanol promotes a single intracellular Ca2+ increase of greater and longer amplitude than the initial increase observed at fertilization. In...

The occurrence of parthenogenetic activation is a major hurdle in obtaining sperm chromosome metaphases after heterospecific intracytoplasmic sperm injection (ICSI) of golden hamster oocytes with human spermatozoa. We addressed two potential contributors to parthenogenetic activation namely, post-ovulatory age of the oocyte and Ca2+ content of the injection medium. In serial experiments, hamste...

Parthenogenetic embryos are an ethically acceptable alternative for the derivation of human embryonic stem cells. In this work, we propose a new strategy to produce bovine parthenogenetic embryos inhibiting the emission of the first polar body during in vitro maturation, and allowing the extrusion of the second polar body during oocyte activation. Cytochalasin B, an inhibitor of actin microfila...

OBJECTIVE To compare directly in vitro developmental competence between parthenogenetically activated and intracytoplasmic sperm injection (ICSI)-fertilized oocytes. DESIGN For each patient, three metaphase II oocytes were randomized to the ICSI procedure, while n-3 were allocated to parthenogenetic activation. SETTING University hospital infertility unit. PATIENTS Thirty-eight patients, ...

Background: Oocyte vitrification and assisted oocyte activation have increasingly important implications in assisted reproductive technology. However, an important area of concern with matured oocyte cryobiology is that elements of oocytes intimately involved in metaphase-II arrest may be modified by cryopreservation. In a comparison between different cellular characteristics of unvitrified, vi...

The aim of this study was to identify an optimal method for the parthenogenetic activation of mouse oocytes. Ethanol (EH), strontium chloride (SrCl2) and ionomycin calcium salt were each combined with cytochalasin B to induce the parthenogenetic activation of CD-1® mouse oocytes. Among the EH combination groups, the blastocyst formation and hatching rates of the group that was activated with EH...