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Synthesis and function of mos: The control switch of vertebrate oocyte meiosis
Author(s) -
Gebauer Fátima,
Richter Joel D.
Publication year - 1997
Publication title -
bioessays
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.175
H-Index - 184
eISSN - 1521-1878
pISSN - 0265-9247
DOI - 10.1002/bies.950190106
Subject(s) - microbiology and biotechnology , maturation promoting factor , xenopus , meiosis , oocyte , prophase , polyadenylation , biology , meiosis ii , oocyte activation , kinase , cyclin dependent kinase 1 , cell cycle , genetics , messenger rna , embryo , cell , gene
One distinguishing feature of vertebrate oocyte meiosis is its discontinuity; oocytes are released from their prophase I arrest, usually by hormonal stimulation, only to again halt at metaphase II, where they await fertilization. The product of the c‐ mos proto‐oncogene, Mos, is a key regulator of this maturation process. Mos is a serine‐threonine kinase that activates and/or stabilizes maturation‐promoting factor (MPF), the master cell cycle switch, through a pathway that involves the mitogen‐activated protein kinase (MAPK) cascade. Oocytes arrested at prophase I lack detectable levels of Mos, which must be synthesized from a pool of maternal mRNAs for proper maturation. While Mos is necessary throughout maturation in Xenopus , it seems to be required only for meiosis II in the mouse. The translational activation of c‐ mos mRNA at specific times during meiosis requires cytoplasmic polyadenylation. Cis‐ and trans ‐acting factors for polyadenylation are, therefore, essential elements of maturation.