The APC is dispensable for first meiotic anaphase in Xenopus oocytes.
Here we show that segregation of homologous chromosomes and that of sister chromatids are differentially regulated in Xenopus and possibly in other higher eukaryotes. Upon hormonal stimulation, Xenopus oocytes microinjected with antibodies against the anaphase-promoting complex (APC) activator Fizzy or the APC core subunit Cdc27, or with the checkpoint protein Mad2, a destruction-box peptide or methylated ubiquitin, readily progress through the first meiotic cell cycle and arrest at second meiotic metaphase. However, they fail to segregate sister chromatids and remain arrested at second meiotic metaphase when electrically stimulated or when treated with ionophore A34187, two treatments that mimic fertilization and readily induce chromatid segregation in control oocytes. Thus, APC is required for second meiotic anaphase but not for first meiotic anaphase.
Peter
M
M
CRBM, UPR 1086 CNRS, 1919 route de Mende, 34293 Montpellier cedex 5, France.
Castro
A
A
Lorca
T
T
Le Peuch
C
C
Magnaghi-Jaulin
L
L
Dorée
M
M
Labbé
J C
JC
D000705:Anaphase / Q000502:physiology*; D064173:Anaphase-Promoting Complex-Cyclosome; D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D000001:Calcimycin / Q000494:pharmacology; D002135:Calcium-Binding Proteins / Q000378:metabolism / Q000494:pharmacology; D002352:Carrier Proteins; D064199:Cdc20 Proteins; D018797:Cell Cycle Proteins / Q000276:immunology / Q000378:metabolism / Q000494:pharmacology; D005260:Female; D005656:Fungal Proteins / Q000378:metabolism / Q000494:pharmacology; D007476:Ionophores / Q000494:pharmacology; D008025:Ligases / Q000502:physiology*; D008540:Meiosis / Q000502:physiology*; D008845:Microinjections; D009687:Nuclear Proteins; D009865:Oocytes / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism; D011374:Progesterone / Q000494:pharmacology; D043743:Ubiquitin-Protein Ligase Complexes; D044767:Ubiquitin-Protein Ligases; D014981:Xenopus / Q000196:embryology* / Q000235:genetics / Q000378:metabolism; D029867:Xenopus Proteins
D000906:Antibodies; D002135:Calcium-Binding Proteins; D002352:Carrier Proteins; D064199:Cdc20 Proteins; C577501:Cdc20 protein, Xenopus; D018797:Cell Cycle Proteins; D005656:Fungal Proteins; D007476:Ionophores; D009687:Nuclear Proteins; D029867:Xenopus Proteins; D000001:Calcimycin; D011374:Progesterone; D043743:Ubiquitin-Protein Ligase Complexes; D064173:Anaphase-Promoting Complex-Cyclosome; D044767:Ubiquitin-Protein Ligases; D008025:Ligases