Toxic effects of Hoechst staining and UV irradiation on preimplantation development of parthenogenetically activated mouse oocytes.
Parthenogenetic activation of oocytes is a helpful tool to obtain blastocysts, of which the inner cell mass may be used for derivation of embryonic stem cells. In order to improve activation and embryonic development after parthenogenesis, we tried to use sperm injection and subsequent removal of the sperm head to mimic the natural Ca2+ increases by release of the oocyte activating factor. Visualization of the sperm could be accomplished by Hoechst staining and ultraviolet (UV) light irradiation. To exclude negative effects of this treatment, we examined toxicity on activated mouse oocytes. After activation, oocytes were incubated in Hoechst 33342 or 33258 stain and exposed to UV irradiation. The effects on embryonic development were evaluated. Our results showed that both types of Hoechst combined with UV irradiation have toxic effects on parthenogenetically activated mouse oocytes. Although activation and cleavage rate were not affected, blastocyst formation was significantly reduced. Secondly, we used MitoTracker staining for removal of the sperm. Sperm heads were stained before injection and removed again after 1 h. However, staining was not visible anymore in all oocytes after intracytoplasmic sperm injection. In case the sperm could be removed, most oocytes died after 1 day. As MitoTracker was also not successful, alternative methods for sperm identification should be investigated.
Department of Reproductive Medicine, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium.
Karen
K
Versieren
Department of Reproductive Medicine, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium.
Björn
B
Heindryckx
Department of Reproductive Medicine, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium.
Chen
C
Qian
Department of Reproductive Medicine, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium.
Jan
J
Gerris
Department of Reproductive Medicine, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium.
Petra
P
De Sutter
D000818:Animals; D001562:Benzimidazoles / Q000633:toxicity*; D001755:Blastocyst / Q000166:cytology* / Q000187:drug effects / Q000528:radiation effects; D002478:Cells, Cultured; D047108:Embryonic Development / Q000187:drug effects* / Q000528:radiation effects*; D005260:Female; D051379:Mice; D008810:Mice, Inbred C57BL; D009865:Oocytes / Q000166:cytology* / Q000187:drug effects / Q000528:radiation effects; D010312:Parthenogenesis / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D011838:Radiation-Sensitizing Agents / Q000633:toxicity; D053625:Sperm Retrieval; D013194:Staining and Labeling / Q000379:methods; D014466:Ultraviolet Rays / Q000009:adverse effects*
D001562:Benzimidazoles; D011838:Radiation-Sensitizing Agents; C017807:bisbenzimide ethoxide trihydrochloride