title: UV irradiation of chromosomal DNA and its effect upon MPF and meiosis in mammalian oocytes.
abstract: 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.
authors.affiliation: Development and Differentiation Laboratory, Babraham Institute, Cambridge, United Kingdom.
authors.forename: J
authors.initials: J
authors.lastname: Bradshaw
authors.forename: T
authors.initials: T
authors.lastname: Jung
authors.forename: J
authors.initials: J
authors.lastname: Fulka
authors.forename: R M
authors.initials: RM
authors.lastname: Moor
mesh_terms: D000818:Animals; D001562:Benzimidazoles / Q000633:toxicity; D002417:Cattle; D002875:Chromosomes / Q000528:radiation effects*; D004247:DNA / Q000528:radiation effects*; D004249:DNA Damage; D005260:Female; D005456:Fluorescent Dyes / Q000633:toxicity; D008297:Male; D016200:Maturation-Promoting Factor / Q000096:biosynthesis*; D008540:Meiosis / Q000528:radiation effects*; D009865:Oocytes / Q000528:radiation effects*; D006656:Protamine Kinase / Q000032:analysis; D013084:Sperm-Ovum Interactions; D014466:Ultraviolet Rays / Q000009:adverse effects
chemical_list: D001562:Benzimidazoles; D005456:Fluorescent Dyes; D004247:DNA; D006656:Protamine Kinase; D016200:Maturation-Promoting Factor; C017807:bisbenzimide ethoxide trihydrochloride