EGG-4 and EGG-5 Link Events of the Oocyte-to-Embryo Transition With Meiotic Progression in C. Elegans

Curr Biol. 2009 Nov 3;19(20):1752-7. doi: 10.1016/j.cub.2009.09.015.

Abstract

The molecular underpinnings of the oocyte-to-embryo transition are poorly understood. Here we show that two protein tyrosine phosphatase-like (PTPL) family proteins, EGG-4 and EGG-5, are required for key events of the oocyte-to-embryo transition in Caenorhabditis elegans. The predicted EGG-4 and EGG-5 amino acid sequences are 99% identical and their functions are redundant. In embryos lacking EGG-4 and EGG-5, we observe defects in meiosis, polar body formation, the block to polyspermy, F-actin dynamics, and eggshell deposition. During oogenesis, EGG-4 and EGG-5 assemble at the oocyte cortex with the previously identified regulators or effectors of the oocyte-to-embryo transition EGG-3, CHS-1, and MBK-2 [1, 2]. All of these molecules share a complex interdependence with regards to their dynamics and subcellular localization. Shortly after fertilization, EGG-4 and EGG-5 are required to properly coordinate a redistribution of CHS-1 and EGG-3 away from the cortex during meiotic anaphase I. Therefore, EGG-4 and EGG-5 are not only required for critical events of the oocyte-to-embryo transition but also link the dynamics of the regulatory machinery with the advancing cell cycle.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Caenorhabditis elegans / embryology*
  • Caenorhabditis elegans / genetics
  • Caenorhabditis elegans / metabolism
  • Caenorhabditis elegans Proteins / analysis
  • Caenorhabditis elegans Proteins / genetics
  • Caenorhabditis elegans Proteins / physiology*
  • Chitin Synthase / analysis
  • Chitin Synthase / genetics
  • Chitin Synthase / physiology
  • Cytoplasm / metabolism
  • Embryonic Development / genetics*
  • Meiosis / physiology*
  • Molecular Sequence Data
  • Oocytes / cytology
  • Oocytes / growth & development
  • Oocytes / metabolism
  • Protein Transport
  • Protein-Tyrosine Kinases / analysis
  • Protein-Tyrosine Kinases / genetics
  • Protein-Tyrosine Kinases / physiology
  • Sequence Alignment

Substances

  • Caenorhabditis elegans Proteins
  • EGG-4 protein, C elegans
  • EGG-5 protein, C elegans
  • Chitin Synthase
  • MBK-2 protein, C elegans
  • Protein-Tyrosine Kinases