Changes in cyclin B localisation during pig oocyte in vitro maturation.
The localisation of cyclin B throughout in vitro maturation of pig oocytes was determined by indirect immunofluorescence using a monoclonal antibody specific for an epitope of the human cyclin B. Maturation of pig oocytes was induced by addition of Pergonal (2 UI/ml of FSH/LH) and beta-oestradiol to the medium where isolated ovarian follicles were cultured for up to 72 h. Immature gametes with an intact germinal vesicle were observed during the first 30 h of culture. Only 10% were competent to reinitiate meiosis and showed germinal vesicle breakdown (GVBD) after 36 h. However, after 48-72 h, 60% of the oocytes accomplished their maturation and showed metaphase chromosomes. Immature oocytes showed cyclin B immunofluorescent staining in the cytoplasm, whereas mature oocytes showed the immunofluorescent label concentrated in the nucleus. Metaphase chromosomes showed an intense immunofluorescence. The migration of cyclin B to the nucleus and its association with metaphase chromosomes in pig oocytes able to progress through meiosis resembled the subcellular localisation of cyclin B and the distribution of maturation promoting factor (MPF) in mitotic dividing cells.
Casas
E
E
Departamento de Ciencias de la Salud, Universidad Autónoma Metropolitana-Iztapalapa, Mexico, DF, Mexico.
Betancourt
M
M
Bonilla
E
E
Duculomb
Y
Y
Zayas
H
H
Trejo
R
R
D000818:Animals; D002478:Cells, Cultured; D003470:Culture Media; D019926:Cyclin B / Q000032:analysis*; D000939:Epitopes / Q000032:analysis; D004958:Estradiol / Q000494:pharmacology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008540:Meiosis; D008596:Menotropins / Q000494:pharmacology; D009865:Oocytes / Q000166:cytology* / Q000187:drug effects; D010053:Ovary / Q000166:cytology; D013552:Swine; D013997:Time Factors
D003470:Culture Media; D019926:Cyclin B; D000939:Epitopes; D004958:Estradiol; D008596:Menotropins