The Control of Meiotic Maturation in Mammalian Oocytes

• Published in: Current Topics in Developmental Biology Vol. 102; pp. 207 - 226
• Main Authors: Holt, Janet E., Lane, Simon I.R., Jones, Keith T.
• Format: Book Chapter Journal Article
• Language: English
• Published: United States Elsevier Science & Technology 2013
• Subjects: Anaphase-promoting complex; Animals; cAMP; CDK1; Cell cycle; Cell Differentiation; Cyclin B1; Female; Fertilization; Humans; Mammals - metabolism; Maturation-promoting factor; Meiosis; Models, Biological; Oocyte; Oocytes - cytology; Signaling; Signaling; Fertilization; Cell cycle; CDK1; Maturation-promoting factor; Female; Meiosis; cAMP; Anaphase-promoting complex; Oocyte; Cyclin B1
• ISBN: 9780124160248; 0124160247
• ISSN: 0070-2153; 1557-8933
• DOI: 10.1016/B978-0-12-416024-8.00007-6

Mammalian oocytes spend the majority of their lives in a dormant state, residing in primordial follicles. This arrest, most analogous to the G2 stage of the mitotic cell cycle division, is only broken in the hours preceding ovulation, when a hormonal rise induces meiotic resumption and entry into the first meiotic division. At a molecular level, this event is triggered by CDK1 activity, and here, we examine how CDK1 is suppressed during meiotic arrest and raised for oocyte maturation. We focus on signaling: intercellular signaling between the oocyte and the somatic cells of the follicle, and spatial signaling involving the anaphase-promoting complex (APC) within the oocyte. Meiotic arrest is achieved through APCFZR1-mediated cyclin B1 degradation. Once meiotic resumption resumes, CDK1 levels rise, but its activity eventually needs to be suppressed for completion of the first meiotic division. This is achieved by APCCDC20, whose activity is critically regulated by the spindle assembly checkpoint, and which induces both a loss in CDK1 activity as well as the cohesive ties holding chromosomes together.