Related Experiment Video

Updated: Aug 9, 2026

Manipulation and In Vitro Maturation of Xenopus laevis Oocytes, Followed by Intracytoplasmic Sperm Injection, to Study Embryonic Development
09:22

Manipulation and In Vitro Maturation of Xenopus laevis Oocytes, Followed by Intracytoplasmic Sperm Injection, to Study Embryonic Development

Published on: February 9, 2015

Progesterone regulates the accumulation and the activation of Eg2 kinase in Xenopus oocytes

M Frank-Vaillant1, O Haccard, C Thibier

  • 1Laboratoire de Physiologie de la Reproduction, INRA/ESA-CNRS 7080, Université Pierre et Marie Curie, boîte 13, 75252 Paris Cédex 05, France.

Journal of Cell Science
|March 8, 2000
PubMed

Insights

Progesterone induces Eg2 protein accumulation in Xenopus oocytes, but this protein kinase is not required for Cdc2 activation during meiotic resumption. Eg2 may organize meiotic spindles.

Area of Science:

  • Cellular and Molecular Biology
  • Developmental Biology
  • Reproductive Biology

Background:

  • Xenopus oocytes resume meiosis upon progesterone stimulation, a process dependent on new protein synthesis and reduced PKA activity.
  • The Aurora/Ipl1 family of protein kinases plays conserved roles in cell division across species.

Purpose of the Study:

  • To investigate the role of Eg2, a Xenopus Aurora/Ipl1 family kinase, in meiotic resumption.
  • To determine if Eg2 accumulation or activity is required for Cdc2 activation in Xenopus oocytes.

Main Methods:

  • Studied Eg2 protein and mRNA levels in response to progesterone and parthenogenetic activation.
  • Utilized an anti-sense strategy to assess the necessity of Eg2 accumulation for Cdc2 activation.
  • Assayed Eg2 kinase activity in relation to Cdc2 activation.

Main Results:

  • Eg2 protein accumulates in response to progesterone, independent of mRNA polyadenylation or cap methylation, and is degraded after parthenogenetic activation.
  • Eg2 accumulation is induced by decreased PKA activity, preceding Cdc2 activation, but Eg2 kinase activity requires Cdc2.
  • Eg2 accumulation is not essential for the signaling pathway leading to Cdc2 activation.

Conclusions:

  • Eg2 protein is not required for progesterone-induced Cdc2 activation in Xenopus oocytes.
  • Eg2 kinase activity is regulated by Cdc2, suggesting a feedback mechanism or downstream role.
  • Eg2 may be involved in meiotic spindle organization, consistent with the known functions of Aurora kinases.

More Related Videos

Xenopus laevis as a Model to Identify Translation Impairment10:24

Xenopus laevis as a Model to Identify Translation Impairment

Published on: September 27, 2015

Xenopus Oocytes: Optimized Methods for Microinjection, Removal of Follicular Cell Layers, and Fast Solution Changes in Electrophysiological Experiments07:24

Xenopus Oocytes: Optimized Methods for Microinjection, Removal of Follicular Cell Layers, and Fast Solution Changes in Electrophysiological Experiments

Published on: December 31, 2016

Related Concept Videos

Oogenesis02:07

Oogenesis

In human women, oogenesis produces one mature egg cell or ovum for every precursor cell that enters meiosis. This process differs in two unique ways from the equivalent procedure of spermatogenesis in males. First, meiotic divisions during oogenesis are asymmetric, meaning that a large oocyte (containing most of the cytoplasm) and minor polar body are produced as a result of meiosis I, and again following meiosis II. Since only oocytes will go on to form embryos if fertilized, this unequal...
Oogenesis01:22

Oogenesis

Oogenesis,  the process of developing egg cells (female gametes), occurs within the ovaries and is fundamental to female fertility. This sequence begins during fetal development when diploid oogonia in the developing ovaries undergo mitotic divisions to produce primary oocytes. By birth, these primary oocytes enter prophase I of meiosis but become arrested in this stage, remaining suspended until puberty.
Each primary oocyte is surrounded by a layer of pre-granulosa cells, forming what is known...