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Manipulation and In Vitro Maturation of Xenopus laevis Oocytes, Followed by Intracytoplasmic Sperm Injection, to Study Embryonic Development
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Synthesis and modification of D7 protein during Xenopus oocyte maturation

R C Smith1, M B Dworkin, E Dworkin-Rastl

  • 1Ernst-Boehringer-Institut, Vienna, Austria.

Molecular Reproduction and Development
|July 1, 1992
PubMed

Insights

Xenopus D7 mRNA is repressed during oogenesis but activated during oocyte maturation. Post-translational modification of D7 protein is also activated during maturation, suggesting a complex regulatory system.

Area of Science:

  • Developmental Biology
  • Molecular Biology
  • Xenopus laevis Research

Background:

  • Maternal mRNA D7 in Xenopus is translationally repressed during oogenesis.
  • D7 protein synthesis is initiated only during oocyte maturation, preceding germinal vesicle breakdown (GVBD).

Purpose of the Study:

  • To investigate the translational regulation of maternal mRNA D7 during Xenopus oocyte maturation.
  • To characterize the synthesis and modification of D7 protein induced by maturation-promoting agents.

Main Methods:

  • Utilizing Xenopus oocytes, maturation-promoting agents (cyclin, c-mos, MPF), and injected D7 RNA.
  • Analyzing protein synthesis and post-translational modifications via molecular weight variants.

Main Results:

  • D7 protein synthesis is induced by maturation agents and undergoes post-translational modification into various molecular weight forms.
  • Injected D7 RNA is efficiently translated, producing unmodified polypeptides that are subsequently modified during maturation.
  • The modification system for D7 protein is activated during oocyte maturation, and this process is not phosphorylation.

Conclusions:

  • The translational control of maternal mRNA D7 is tightly regulated during Xenopus oocyte maturation.
  • Post-translational modification of D7 protein is a key event activated during maturation, independent of exogenous D7 RNA translation.
  • This study elucidates a novel regulatory mechanism involving translational repression and activation of post-translational modification during early development.

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