Synergistic effect of A23187 and cycloheximide allows effective activation of freshly matured bovine oocytes

Nuclear dynamics of parthenogenesis of bovine oocytes matured in vitro for 20 and 40 hours and activated with combined ethanol and cycloheximide treatment

“…In our combined treatment regimen, ethanolinduced Ca2+ elevation would inactivate the existing CSF, and the subsequent cycloheximide exposure would prevent renewal of CSF synthesis in the oocyte. This also explains why practically 100% of the MI1 oocytes were driven out of metaphase to the pronuclear stage by this combined treatment or similar combined treatments (Yang et al, 1992;Presicce and Yang, 1993;Shi et al, 1993).…”

“…Application of this procedure to induce pronuclear formation in cattle oocytes has been reported to have achieved some success (Sirard et al, 1989). Recently, we demonstrated that combined treatments with calcium-elevating agents (electric pulse, ethanol, or calcium ionophore) and a protein synthesis inhibitor, cycloheximide, effectively drove oocytes to resume meiosis and induced oocyte activation in a nonage-dependent fashion (Yang et al, 1992(Yang et al, , 1993bShi et al, 1993). This is very encouraging for nuclear transfer research and practice, because nuclear transfer following a similar combined activation treatment suggests that young, freshly matured bovine IVM oocytes may be used effectively as nuclear cytoplasmic recipients Leibfried-Rutledge et al, 1992).…”

Parthenogenetic development of bovine oocytes matured in vitro for 24 hr and activated by ethanol and cycloheximide

“…High levels of MPF is known to be essential for meiotic arrest of mammalian oocytes, and thus its breakdown would induce resumption of meiosis or activation of the oocytes. This hypothesis has been demonstrated to be true for activating oocytes with several other Ca2+ elevating agents, such as electric pulse or calcium ionophore in combination with cycloheximide (First et al, 1992, Moses andMasui, 1991;Presicce and Yang, 1993;Shi et al, 1993;. However, little information is available on parthenogenetic development, particularly blastocyst development following activation of IVM bovine oocytes by these procedures.…”

“…tion agents has been demonstrated to be oocyte age dependent (Nagai, 1987;Kubiak, 1989; Ware et al, 1989). Less than 40% of the young (23-24 hr) in vitromatured (IVM) bovine oocytes developed to pronuclear stage following activation treatment by ethanol (Nagai, 1987; Yang et al, 1993~1, calcium ionophore (Ware et al, 1989;Shi et al, 1993), electric pulse (First et al, 1992;Ware et al, 1989;Yang et al, 1993~1, or cycloheximide (First, et al, 1992;Shi et al, 1993;Yang et al, 1993~). For this reason, most nuclear transfer programs involved using aging oocytes (Barnes et al, 1993;Bondioli et al, 1990; Stice and Keefer, 1993;Westhusin et al, 1992;Willadsen et al, 1991) or aging cytoplast (Yang et al, 199313).…”

Effects of Artificial Stimulations on the activation of oocyte and the expression of cyclin B1 protein in mouse oocytes

“…The use of enucleated oocytes stimulated could increase the frequency of development to blastocyst in embryos reconstructed from unsynchronized donor blastomeres (Campbell et al, 1993). To activate the enucleated oocytes, several calcium-elevating agents, such as ethanol --354 (Minamihashi et al, 1993) or calcium ionophore (Ware et al, 1989;Shi et al, 1993) have been used. Recently, protein synthesis inhibitors, like cycloheximide or 6-dimethylaminopurine (6-DMAP) have been used simultaneously with calciumelevating agents to increase the higher oocyte activation and development rate .…”