title: Induction of reinitiation of meiosis in amphibian Bufo oocytes by injection of ciliate Paramecium extracts.
abstract: Germinal vesicle breakdown (GVBD) of amphibian Bufo oocytes can be induced if Paramecium extracts were injected into them. The activity of meiosis-reinitiation-inducing factor (MRIF) appeared in premeiotic G1 cells, then the activity fluctuates according to the degrees of micronuclear chromatin condensation in meiosis. Proliferating micronucleate and amicronucleate cells also showed the same activity. MRIF differed from MPF (M phase promoting factor), because MRIF appeared not only in M phase cells but also in premeiotic interphase cells and its action on the induction of GVBD was inhibited by cycloheximide. Preliminary experiments showed that MRIF was a heat-labile soluble protein.
authors.affiliation: Biological Institute, Faculty of Science, Yamaguchi University, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Fujishima
authors.forename: M
authors.initials: M
authors.lastname: Hori
mesh_terms: D000818:Animals; D001681:Biological Assay; D002025:Bufonidae / Q000196:embryology*; D002455:Cell Division; D002458:Cell Fractionation; D003513:Cycloheximide / Q000494:pharmacology; D008540:Meiosis / Q000187:drug effects; D009865:Oocytes / Q000166:cytology*; D010247:Paramecium / Q000166:cytology*; D011506:Proteins / Q000502:physiology; D012260:Ribonucleases / Q000494:pharmacology; D013696:Temperature; D014357:Trypsin / Q000494:pharmacology
chemical_list: D011506:Proteins; D003513:Cycloheximide; D012260:Ribonucleases; D014357:Trypsin