MAP kinase inactivation is required only for G2-M phase transition in early embryogenesis cell cycles of the starfishes Marthasterias glacialis and Astropecten aranciacus.
Downregulation of MAP kinase is a universal consequence of fertilization in the animal kingdom. Here we show that oocytes of the starfishes Astropecten aranciacus and Marthasterias glacialis complete meiotic maturation and form a pronucleus when treated with 1-methyladenine and then complete DNA replication and arrest at G2 if not fertilized. Release of G2 by fertilization or a variety of parthenogenetic treatments is associated with inactivation of MAP kinase. Prevention of MAP kinase inactivation by microinjection of Ste11-DeltaN, a constitutively active budding yeast MAP kinase kinase kinase, arrests fertilized eggs at G2 in either the first or the second mitotic cell cycle, in a dose-dependent manner. G1 arrest is never observed. Conversely, inactivation of MAP kinase by microinjection of the MAP kinase-specific phosphatase Pyst-1 releases mature starfish oocytes from G2 arrest. The role of MAP kinase in arresting cell cycle at various stages in oocytes of different animal species is discussed.
Fisher
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CRBM CNRS ERS 155, 1919 route de mende, Montpellier cedex 5, 34293, France.
Abrieu
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Simon
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MN
Keyse
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Vergé
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Dorée
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Picard
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D000225:Adenine / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D018385:Centrosome; D004261:DNA Replication; D054642:Dual Specificity Phosphatase 6; D004533:Egtazic Acid / Q000494:pharmacology; D005306:Fertilization; D005656:Fungal Proteins / Q000235:genetics / Q000494:pharmacology; D016195:G2 Phase / Q000502:physiology*; D007476:Ionophores / Q000494:pharmacology; D008540:Meiosis / Q000502:physiology; D008938:Mitosis / Q000502:physiology; D009865:Oocytes; D010312:Parthenogenesis; D017027:Protein Tyrosine Phosphatases / Q000235:genetics; D012333:RNA, Messenger / Q000494:pharmacology; D029702:Schizosaccharomyces pombe Proteins; D017384:Sequence Deletion; D013215:Starfish / Q000196:embryology* / Q000201:enzymology; D014157:Transcription Factors / Q000235:genetics / Q000494:pharmacology
D005656:Fungal Proteins; D007476:Ionophores; D012333:RNA, Messenger; D029702:Schizosaccharomyces pombe Proteins; D014157:Transcription Factors; C071596:ste11 protein, S pombe; C008407:1-methyladenine; D004533:Egtazic Acid; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D054642:Dual Specificity Phosphatase 6; D017027:Protein Tyrosine Phosphatases; D000225:Adenine