Oocyte maturation, Mos and cyclins--a matter of synthesis: two functionally redundant ways to induce meiotic maturation.
The development of an immature oocyte into a fertilizable gamete is a process known as meiotic maturation. In vertebrates, it corresponds to the transition from the prophase arrest of the first meiotic division (usually considered as a late G(2) phase) to the metaphase arrest of the second meiotic division. This transition is controlled by modulating the activity of the cyclin B-Cdc2 complex, MPF (M-phase promoting factor), the universal regulator of the G(2)/M transition. Meiotic maturation of frog oocytes is triggered by steroid hormones through a rapid, necessary and sufficient suppression of PKA and requires ongoing protein synthesis. A long-standing question has been to identify key protein(s) required to trigger the activation of MPF in response to the hormonal signal. Here we will discuss data supporting the view that steroids bring about meiotic maturation through functionally redundant pathways involving synthesis of Mos or of cyclin proteins, reinforcing the robustness of the system.
Haccard
Olivier
O
Laboratoire de Biologie du Développement, Equipe Biologie de l'Ovocyte UMR CNRS 7622, Université Pierre et Marie Curie, Paris, France.
Jessus
Catherine
C
D029845:Amphibian Proteins; D000663:Amphibians; D000818:Animals; D016213:Cyclins / Q000502:physiology*; D005854:Germ Cells / Q000166:cytology; D008540:Meiosis; D009865:Oocytes / Q000502:physiology*; D017231:Proto-Oncogene Proteins c-mos / Q000502:physiology*; D015398:Signal Transduction; D013256:Steroids / Q000494:pharmacology
D029845:Amphibian Proteins; D016213:Cyclins; D013256:Steroids; D017231:Proto-Oncogene Proteins c-mos