EGG-3 regulates cell-surface and cortex rearrangements during egg activation in Caenorhabditis elegans

Curr Biol. 2007 Sep 18;17(18):1555-60. doi: 10.1016/j.cub.2007.08.011.


Fertilization triggers egg activation and converts the egg into a developing embryo. The events of this egg-to-embryo transition typically include the resumption of meiosis, the reorganization of the cortical actin cytoskeleton, and the remodeling of the oocyte surface. The factors that regulate sperm-dependent egg-activation events are not well understood. Caenorhabditis elegans EGG-3, a member of the protein tyrosine phosphatase-like (PTPL) family, is essential for regulating cell-surface and cortex rearrangements during egg activation in response to sperm entry. Although fertilization occurred normally in egg-3 mutants, the polarized dispersal of F-actin is altered, a chitin eggshell is not formed, and no polar bodies are produced. EGG-3 is associated with the oocyte plasma membrane in a pattern that is similar to CHS-1 and MBK-2. CHS-1 is required for eggshell deposition, whereas MBK-2 is required for the degradation of maternal proteins during the egg-to-embryo transition. The localization of CHS-1 and EGG-3 are interdependent and both genes were required for the proper localization of MBK-2 in oocytes. Therefore, EGG-3 plays a central role in egg activation by influencing polarized F-actin dynamics and the localization or activity of molecules that are directly involved in executing the egg-to-embryo transition.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / analysis
  • Actins / metabolism
  • Amino Acid Motifs
  • Animals
  • Caenorhabditis elegans / embryology*
  • Caenorhabditis elegans / genetics
  • Caenorhabditis elegans / metabolism
  • Caenorhabditis elegans Proteins / analysis
  • Caenorhabditis elegans Proteins / chemistry
  • Caenorhabditis elegans Proteins / metabolism
  • Caenorhabditis elegans Proteins / physiology*
  • Cell Membrane / metabolism
  • Embryo, Nonmammalian / cytology
  • Embryo, Nonmammalian / metabolism
  • Fertilization
  • Green Fluorescent Proteins / analysis
  • Molecular Sequence Data
  • Ovum / cytology
  • Ovum / growth & development*
  • Ovum / metabolism
  • Protein Tyrosine Phosphatases / chemistry
  • Protein Tyrosine Phosphatases / metabolism
  • Protein Tyrosine Phosphatases / physiology*
  • Protein-Tyrosine Kinases / analysis
  • Protein-Tyrosine Kinases / metabolism


  • Actins
  • Caenorhabditis elegans Proteins
  • Green Fluorescent Proteins
  • MBK-2 protein, C elegans
  • Protein-Tyrosine Kinases
  • EGG-3 protein, C elegans
  • Protein Tyrosine Phosphatases