Ca2+ homeostasis regulates Xenopus oocyte maturation

Lu Sun, Rawad Hodeify, Shirley Haun, Amanda Charlesworth, Angus M. MacNicol, Subramaniam Ponnappan, Usha Ponnappan, Claude Prigent, Khaled Machaca

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In contrast to the well-defined role of Ca2+ signals during mitosis, the contribution of Ca2+ signaling to meiosis progression is controversial, despite several decades of investigating the role of Ca 2+ and its effectors in vertebrate oocyte maturation. We have previously shown that during Xenopus oocyte maturation, Ca2+ signals are dispensable for entry into meiosis and for germinal vesicle breakdown. However, normal Ca2+ homeostasis is essential for completion of meiosis I and extrusion of the first polar body. In this study, we test the contribution of several downstream effectors in mediating the Ca2+ effects during oocyte maturation. We show that calmodulin and calcium-calmodulin-dependent protein kinase II (CAMK2) are not critical downstream Ca2+ effectors during meiotic maturation. In contrast, accumulation of Aurora kinase A (AURKA) protein is disrupted in cells deprived of Ca2+ signals. Since AURKA is required for bipolar spindle formation, failure to accumulate AURKA may contribute to the defective spindle phenotype following Ca2+ deprivation. These findings argue that Ca2+ homeostasis is important in establishing the oocyte's competence to undergo maturation in preparation for fertilization and embryonic development.

Original languageEnglish
Pages (from-to)726-735
Number of pages10
JournalBiology of Reproduction
Issue number4
Publication statusPublished - Apr 2008
Externally publishedYes



  • Aurora kinase A
  • Calcium
  • Gamete biology
  • Meiosis
  • Oocyte development

ASJC Scopus subject areas

  • Cell Biology
  • Developmental Biology
  • Embryology

Cite this

Sun, L., Hodeify, R., Haun, S., Charlesworth, A., MacNicol, A. M., Ponnappan, S., Ponnappan, U., Prigent, C., & Machaca, K. (2008). Ca2+ homeostasis regulates Xenopus oocyte maturation. Biology of Reproduction, 78(4), 726-735.