Phospholipase C-ζ-induced Ca2+ oscillations cause coincident cytoplasmic movements in human oocytes that failed to fertilize after intracytoplasmic sperm injection

Fertil Steril. 2012 Mar;97(3):742-7. doi: 10.1016/j.fertnstert.2011.12.013. Epub 2012 Jan 2.


Objective: To evaluate the imaging of cytoplasmic movements in human oocytes as a potential method to monitor the pattern of Ca(2+) oscillations during activation.

Design: Test of a laboratory technique.

Setting: University medical school research laboratory.

Patient(s): Donated unfertilized human oocytes from intracytoplasmic sperm injection (ICSI) cycles.

Intervention(s): Microinjection of oocytes with phospholipase C (PLC) zeta (ζ) cRNA and a Ca(2+)-sensitive fluorescent dye.

Main outcome measure(s): Simultaneous detection of oocyte cytoplasmic movements using particle image velocimetry (PIV) and of Ca(2+) oscillations using a Ca(2+)-sensitive fluorescent dye.

Result(s): Microinjection of PLCζ cRNA into human oocytes that had failed to fertilize after ICSI resulted in the appearance of prolonged Ca(2+) oscillations. Each transient Ca(2+) concentration change was accompanied by a small coordinated movement of the cytoplasm that could be detected using PIV analysis.

Conclusion(s): The occurrence and frequency of cytoplasmic Ca(2+) oscillations, a critical parameter in activating human zygotes, can be monitored by PIV analysis of cytoplasmic movements. This simple method provides a novel, noninvasive approach to determine in real time the occurrence and frequency of Ca(2+) oscillations in human zygotes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Calcium Signaling*
  • Cytoplasm / enzymology*
  • Female
  • Fluorescent Dyes / administration & dosage
  • Humans
  • Male
  • Microinjections
  • Microscopy, Fluorescence
  • Motion
  • Oocytes / enzymology*
  • Phosphoinositide Phospholipase C / genetics
  • Phosphoinositide Phospholipase C / metabolism*
  • RNA, Complementary / administration & dosage
  • Rheology
  • Sperm Injections, Intracytoplasmic*
  • Time Factors
  • Treatment Failure


  • Fluorescent Dyes
  • RNA, Complementary
  • PLCZ1 protein, human
  • Phosphoinositide Phospholipase C