Calcium oscillations and protein synthesis inhibition synergistically activate mouse oocytes

✍ Scribed by A. Bos-Mikich; K. Swann; D. G. Whittingham

• Book ID: 102951652
• Publisher: John Wiley and Sons
• Year: 1995
• Tongue: English
• Weight: 827 KB
• Volume: 41
• Category: Article
• ISSN: 1040-452X
• DOI: 10.1002/mrd.1080410113

✦ Synopsis

We have examined the ability of the two parthenogenetic agents, strontium (Sr2') and cycloheximide, to activate mouse oocytes. W e demonstrate that Sr2+ and cycloheximide act synergistically to promote Parthenogenetic activation up to the pronuclear stage in oocytes collected immediately after ovulation. These two agents appeared to act independently, since incubation in Srz+ media triggered a series of intracellular Ca2+ rises without affecting protein synthesis and cycloheximide inhibited protein synthesis without causing any intracellular Ca2+ changes. In addition, cycloheximide did not alter the pattern of Ca2+ oscillations induced by Sr" . In contrast, we show that another commonly used parthenogenetic activation treatment, the Ca2+ ionophore A23187, has dual effects. Exposure of oocytes to the Ca2+ ionophore, A 23187, in Ca2' -and Mg2+-free medium leads to the activation of young oocytes. However, as well as generating a Ca2+ increase, the treatment of mouse oocytes with A23187 and Ca2+and Mg*+-free media led to a marked inhibition of protein synthesis. Our data show that parthenogenetic agents may have two important loci for activating mammalian oocytes and that the combined effect on Ca2+ release and protein synthesis is most effective.