Parthenogenetic activation is a procedure that an oocyte at meiosis II stage is activated into mitosis by some chemical or physical stimulation other than a sperm and the embryo is formed in the absence of any contribution from a male gamete. The activation of oocyte is the result of calcium ion oscillations and deactivation of some cytokines such as maturation promoting factor, mitogen-activated protein kinase and cytostatic factor. Parthenogenetic activation is artificially induced by various kinds of physical and/or chemical methods. The main activation method of human oocyte is chemical methods. The rates of activation and cleavage depend on the age, origin,and culture conditions of the oocyte.
Adenine ; analogs & derivatives ; pharmacology ; Animals ; Calcium ; metabolism ; Cycloheximide ; pharmacology ; Cytokines ; metabolism ; Female ; Humans ; Oocytes ; drug effects ; growth & development ; metabolism ; Parthenogenesis ; drug effects

This study was conducted to investigate the effects of rapamycin treatment during in vitro maturation (IVM) on oocyte maturation and embryonic development after parthenogenetic activation (PA) and somatic cell nuclear transfer (SCNT) in pigs. Morphologically good (MGCOCs) and poor oocytes (MPCOCs) were untreated or treated with 1 nM rapamycin during 0-22 h, 22-42 h, or 0-42 h of IVM. Rapamycin had no significant effects on nuclear maturation and blastocyst formation after PA of MGCOCs. Blastocyst formation after PA was significantly increased by rapamycin treatment during 22-42 h and 0-42 h (46.6% and 46.5%, respectively) relative to the control (33.3%) and 0-22 h groups (38.6%) in MPCOCs. In SCNT, blastocyst formation tended to increase in MPCOCs treated with rapamycin during 0-42 h of IVM relative to untreated oocytes (20.3% vs. 14.3%, 0.05 < p < 0.1), while no improvement was observed in MGCOCs. Gene expression analysis revealed that transcript abundance of Beclin 1 and microtubule-associated protein 1 light chain 3 mRNAs was significantly increased in MPCOCs by rapamycin relative to the control. Our results demonstrated that autophagy induction by rapamycin during IVM improved developmental competence of oocytes derived from MPCOCs.
Animals ; Embryonic Development/*drug effects ; Female ; In Vitro Oocyte Maturation Techniques/veterinary ; Nuclear Transfer Techniques/*veterinary ; Oocytes/growth & development ; *Parthenogenesis ; Sirolimus/*pharmacology ; Sus scrofa/*growth & development/metabolism

This study was conducted to establish an in vitro maturation (IVM) system by selection of efficient porcine serum during porcine in vitro production. To investigate the efficient porcine serum (PS), different types of PS [newborn pig serum, prepubertal gilt serum (PGS), estrus sow serum, and pregnancy sow serum] were used to supplement IVM media with or without gonadotrophin (GTH) and development rates of parthenogenetic activation (PA) and in vitro fertilization (IVF) embryos were then compared. The maturation rates of the PGS group was significantly higher when GTH was not added. Additionally, during development of PA embryos without GTH, the PGS group showed significantly higher cleavage and blastocyst formation rates. Moreover, the cleavage rates of IVF embryos were significantly higher in the PGS group, with no significant differences in the blastocyst formation. However, when GTH was supplemented into the IVM media, there were no significant differences among the four groups in the cleavage rates, development rates of the blastocyst, and cell number of the blastocyst after PA and IVF. In conclusion, PGS is an efficient macromolecule in porcine IVM, and GTH supplementation of the IVM media is beneficial when PS is used as macromolecule, regardless of its origin.
Animals ; Blastocyst/*drug effects ; Embryo, Mammalian/drug effects/*embryology/physiology/ultrastructure ; Fertilization in Vitro/veterinary ; Gonadotropins/administration & dosage/*metabolism ; In Vitro Oocyte Maturation Techniques/*methods/veterinary ; Parthenogenesis/*drug effects ; Sus scrofa/*embryology

For parthenogenetic activation as a model system of nuclear transfer, microinjection and electroporation as activation treatments in bovine metaphase II oocytes were administered to each of three groups as follows: control group (treatments with Ca2+, Mg2+ -free PBS+100 micro M EGTA), IP3 group (control+25 micro M IP3) and IP3+ ryanodine group (control+25 micro M IP3+10 mM ryanodine). In experiments using microinjection, no significant differences were observed between any of the developmental stages of the electroporation experiment. For electroporation, cleavage rates were significantly higher in the IP3+ryanodine group than in the IP3 or control group (85.6% vs 73.7% or 67.6%, respectively). In the subsequent stages of embryonic development, such as morula and blastocyst formation, the IP3 and ryanodine group exhibited significantly higher rates of morula fomation than the IP3 or control groups (40.6% vs 24.2% or 16.7%, respectively). Similarly, the rate of blastocyst formation in the IP3+ryanodine group was significantly higher than the control group (16.3% vs 6.9%) but did not differ significantly from the IP3 group (16.3% vs 9.5%). In nuclear transfer, activation was performed at 30 hpm by microinjection and elecroporation with 25 micro M IP3+ 10 mM ryanodine followed by 6-DMAP treatment. No significant differences were observed at any stage of embryonic development and none of the embryos activated by electroporation reached either the morula or blastocyst stage. However, 3.8% and 1.9% of embryos activated by microinjection sucessfully developed to the morula and blastocyst stages, respectively. In conclusion, activation treatments using IP3 and ryanodine are able to support the development of bovine parthenogenetic and reconstructed embryos.
Adenine/administration & dosage/*analogs & derivatives/pharmacology ; Animals ; Cattle/*embryology/physiology ; Cell Fusion ; Electroporation/veterinary ; Embryonic and Fetal Development/*drug effects ; Enzyme Inhibitors/administration & dosage/pharmacology ; Female ; Inositol 1,4,5-Trisphosphate/administration & dosage/*pharmacology ; Microinjections/veterinary ; Nuclear Transfer Techniques ; Oocytes/drug effects/growth & development ; Parthenogenesis/*drug effects ; Protein Kinase Inhibitors ; Ryanodine/administration & dosage/*pharmacology ; Skin/cytology