title: The effects of proteasome inhibitor lactacystin on mouse oocyte meiosis and first cleavage.
abstract: In order to study the effects of ubiquitin-proteasome pathway (UPP) on mouse oocyte meiosis and cleavage, oocytes undergoing maturation and parthenogenetic activation and 1-cell embryos were treated with lactacystin, a specific inhibitor of proteasome. The results indicated that the rate of GVBD was not influenced by the treatment, but polar body extrusion, parthenogenesis and first cleavage were inhibited. Immunofluorescent staining using anti beta-tubulin antibody indicated that the continuous treatment of lactacystin from GV stage disorganized microtubules and spindle assembly. When metaphase stage oocytes were treated with the drug, the already formed spindle structure was not affected, but the oocytes were arrested at metaphases. The 1-cell embryos were arrested at interphase or metaphase of first mitosis when they were incubated in the drug. Proteasome regulatory subunit PA700 was located in the spindle region, as indicated by immunofluorescence. These results suggest that UPP has effects on the process of oocyte meiosis and early cleavage in many aspects, including normal organization of spindle at prophase and segregation of chromosomes at anaphase for normal meiosis.
authors.affiliation: School of Life Sciences and Technology, Beijing Institute of Technology, Beijing 100081, China. tanxing@bit.edu.cn
authors.forename: Xin
authors.initials: X
authors.lastname: Tan
authors.forename: An
authors.initials: A
authors.lastname: Peng
authors.forename: Yongchao
authors.initials: Y
authors.lastname: Wang
authors.forename: Zuoqing
authors.initials: Z
authors.lastname: Tang
mesh_terms: D000111:Acetylcysteine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D002455:Cell Division / Q000187:drug effects; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005260:Female; D008297:Male; D008540:Meiosis / Q000187:drug effects*; D051379:Mice; D018613:Microscopy, Confocal; D008870:Microtubules / Q000187:drug effects / Q000378:metabolism; D009865:Oocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D061988:Proteasome Inhibitors; D015053:Zygote / Q000166:cytology / Q000187:drug effects / Q000378:metabolism
chemical_list: D015853:Cysteine Proteinase Inhibitors; D061988:Proteasome Inhibitors; C067713:lactacystin; D046988:Proteasome Endopeptidase Complex; D000111:Acetylcysteine