The role of protein kinase C in reorganization of the cortical cytoskeleton during the transition from oocyte to fertilization‐competent egg

David Capco, J. M. Tutnick, W. M. Bement

Research output: Contribution to journalArticle

20 Scopus citations

Abstract

Fertilization‐competent amphibian eggs (metaphase II) are programmed to undergo an actin‐myosin based contraction of the cortical cytoplasm (i.e., cortical contraction) in response to an elevation of intracellular‐free calcium which accompanies fertilization. This ability to undergo cortical contraction is acquired within a few hours after the meiotically‐arrested oocyte is triggered to resume meiosis by exposure to progesterone. This report examines the timing of changes in the contractile potential of the cortical cytoplasm as the oocyte becomes the egg, and in addition, the signal transduction events which induce these changes. We use the bisected oocyte system developed by Christensen et al. ('84; Nature 310: 150‐151) to assess the changes in cortical potential during the meiotic resumption. Immediately after progesterone treatment (less than 5% of the way through the meiotic resumption) the cortex acquires the ability to form a contractile ring, an ability which gradually disappears during the meiotic resumption. Eighty percent of the way through the meiotic resumption the cortex of the hemisphere rapidly acquires the ability to undergo cortical contraction. In contrast, when bisected in a medium containing protein kinase C (PKC) agonists, the cortex of the hemisphere undergoes cortical contraction much earlier (i.e., 50% through the meiotic resumption). In addition, treatment of oocytes with PKC agonists alone can mimic the complete spectrum of changes in cortical potential induced by progesterone, suggesting that PKC has a role in reorganization of the cortical cytoskeleton which occurs as a normal response to progesterone. In support of this, antagonists of PKC block the progesterone‐induced reorganization of the cortical cytoskeleton. © 1992 Wiley‐Liss, Inc.

Original languageEnglish (US)
Pages (from-to)395-405
Number of pages11
JournalJournal of Experimental Zoology
Volume264
Issue number4
DOIs
StatePublished - Dec 15 1992

ASJC Scopus subject areas

  • Animal Science and Zoology

Fingerprint Dive into the research topics of 'The role of protein kinase C in reorganization of the cortical cytoskeleton during the transition from oocyte to fertilization‐competent egg'. Together they form a unique fingerprint.

  • Cite this