Bradshaw J, Jung T, Fulka J, Moor R M
Development and Differentiation Laboratory, Babraham Institute, Cambridge, United Kingdom.
Mol Reprod Dev. 1995 Aug;41(4):503-12. doi: 10.1002/mrd.1080410413.
Bovine oocytes were irradiated at germinal vesicle (GV) or metaphase II (MII) stage, after Hoechst staining, with chromosomally focused UV-C (254 nm) or UV-A ( > 330 nm). UV-C irradiation at GV stage did not inhibit germinal vesicle breakdown (GVBD) or chromosomal condensation; spindle formation was abolished and maturation promoting factor (MPF) levels failed to increase. UV-A irradiation at GV stage caused meiotic arrest at anaphase I; MPF levels were lower than control. UV-C irradiation at MII stage led to subsequent abnormal parthenogenetic activation when MPF levels failed to decrease. A normal male but no female pronucleus was formed at fertilization. UV-A irradiation at MII stage also caused abnormal activation; MPF levels declined normally. A normal male and abnormal female pronucleus formed at fertilization. UV-A irradiation results have implications for oocyte evaluation during development using Hoechst staining. UV-C irradiation is a potential means for oocyte enucleation in nuclear transfer.
