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Updated: Jun 27, 2026
Mouse Oocyte Microinjection, Maturation and Ploidy Assessment
Published on: July 23, 2011
Effect of ionomycin on oocyte activation and embryo development in mouse
Elke Heytens1, Reza Soleimani, Sylvie Lierman
1Centre for Reproductive Medicine, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium. Elke.Heytens@UGent.be
Abstract:
Artificial oocyte activation using the calcium ionophore ionomycin is applied successfully in assisted reproduction but some concern exists on the clinical use. The aims of the present study were to optimize the oocyte activation scheme and to address embryo toxicity in a mouse model. Efficiency of oocyte activation and subsequent development was evaluated and ionomycin was found to be an efficient activator at 10 micromol/l. An improved effect of a second exposure to 5 micromol/l ionomycin on blastocyst development was observed. Toxicity of ionomycin on embryos was then investigated by evaluating pre- and post-implantation development of in-vivo fertilized oocytes following exposure to ionomycin. Blastocyst development, blastocyst cell numbers in trophectoderm and inner cell mass were not different between treated and non-treated zygotes. Also implantation rates and fetal parameters such as length, weight and morphological parameters were similar between the fetuses originating from zygotes treated with ionomycin and non-treated zygotes. Furthermore, healthy offspring originating from ionomycin-treated zygotes was born. In conclusion, no adverse effects of ionomycin on in-vitro or in-vivo mouse embryo development were noticed, giving arguments in favour of the use of ionomycin, although negative long-term effects of this compound cannot be excluded at present.
Insights
Artificial oocyte activation with ionomycin is effective in assisted reproduction. Studies in mice show ionomycin has no adverse effects on embryo development or offspring health, supporting its clinical use.
Area of Science:
- Reproductive Biology
- Developmental Biology
- Assisted Reproductive Technology
Background:
- Artificial oocyte activation is crucial in assisted reproduction.
- The calcium ionophore ionomycin is widely used but raises concerns about clinical safety.
- Optimizing ionomycin protocols and assessing its embryo toxicity are essential.
Purpose of the Study:
- To optimize the artificial oocyte activation protocol using ionomycin.
- To evaluate the toxicity of ionomycin on mouse embryo development in vitro and in vivo.
- To assess the impact of ionomycin on pre- and post-implantation development and fetal parameters.
Main Methods:
- Oocyte activation efficiency and subsequent embryo development were assessed using varying ionomycin concentrations (10 µmol/L and 5 µmol/L).
- Embryo toxicity was evaluated by examining blastocyst development, cell counts (trophectoderm and inner cell mass), implantation rates, and fetal parameters.
- In vivo fertilization and post-implantation development of oocytes exposed to ionomycin were analyzed.
Main Results:
- Ionomycin effectively activated oocytes at 10 µmol/L, with a second exposure to 5 µmol/L improving blastocyst development.
- No significant differences were observed in blastocyst development, cell numbers, implantation rates, or fetal parameters between ionomycin-treated and control groups.
- Healthy offspring were born from ionomycin-treated zygotes, indicating no immediate adverse effects.
Conclusions:
- Ionomycin is an efficient agent for artificial oocyte activation.
- The study found no evidence of ionomycin-induced toxicity on mouse embryo development or fetal parameters in vitro or in vivo.
- These findings support the use of ionomycin in assisted reproduction, though long-term effects warrant further investigation.
