Mammalian phospholipase Czeta induces oocyte activation from the sperm perinuclear matrix

Dev Biol. 2004 Oct 15;274(2):370-83. doi: 10.1016/j.ydbio.2004.07.025.


Mammalian sperm-borne oocyte activating factor (SOAF) induces oocyte activation from a compartment that engages the oocyte cytoplasm, but it is not known how. A SOAF-containing extract (SE) was solubilized from the submembrane perinuclear matrix, a domain that enters the egg. SE initiated activation sufficient for full development. Microinjection coupled to tandem mass spectrometry enabled functional correlation profiling of fractionated SE without a priori assumptions about its chemical nature. Phospholipase C-zeta (PLCzeta) correlated absolutely with activating ability. Immunoblotting confirmed this and showed that the perinuclear matrix is the major site of 72-kDa PLCzeta. Oocyte activation was efficiently induced by 1.25 fg of sperm PLCzeta, corresponding to a fraction of one sperm equivalent (approximately 0.03). Immunofluorescence microscopy localized sperm head PLCzeta to a post-acrosomal region that becomes rapidly exposed to the ooplasm following gamete fusion. This multifaceted approach suggests a mechanism by which PLCzeta originates from an oocyte-penetrating assembly--the sperm perinuclear matrix--to induce mammalian oocyte activation at fertilization.

MeSH terms

  • Animals
  • Cell Fractionation
  • Female
  • Fertilization / physiology
  • Humans
  • Male
  • Mice
  • Microinjections
  • Molecular Sequence Data
  • Nuclear Matrix / chemistry
  • Nuclear Matrix / enzymology
  • Oocytes / cytology
  • Oocytes / physiology*
  • Phosphoinositide Phospholipase C
  • Sperm-Ovum Interactions*
  • Spermatozoa / chemistry
  • Spermatozoa / cytology
  • Spermatozoa / enzymology*
  • Swine
  • Type C Phospholipases / chemistry
  • Type C Phospholipases / genetics
  • Type C Phospholipases / metabolism*


  • Type C Phospholipases
  • PLCZ1 protein, human
  • Phosphoinositide Phospholipase C
  • Plcz1 protein, mouse