NAADP triggers the fertilization potential in starfish oocytes

Francesco Moccia, Dmitry Lim, Keiichiro Kyozuka, Luigia Santella

Research output: Contribution to journalArticlepeer-review

48 Citations (Scopus)


In invertebrates oocytes or eggs, the fertilization or activation potential establishes the fast electrical block to polyspermy and, in some species, provides the Ca2+ influx which contributes to the following intracellular Ca2+ wave. In echinoderms, the molecule triggering the activation potential is still unknown. The aim of this study was to assess whether nicotinic acid-adenine dinucleotide phosphate (NAADP) elicited the fertilization potential in starfish oocytes. The changes in membrane potential induced by the sperm were measured in oocytes held at a low resting potential, so that the Ca2+-action potential was inactivated and only the initial slower depolarization caused by the sperm could be studied. Decreasing extracellular Na+ concentration did not prevent the onset of the fertilization potential, while removal of external Ca2+ abolished it. The pre-incubation with SK&F 96365 and verapamil and the pre-injection of BAPTA inhibited the fertilization potential, while the injection of heparin only reduced its duration. The biophysical and pharmacological properties of the sperm-elicited depolarization were similar to those displayed by the NAADP-activated Ca2+-mediated current recently described in starfish oocytes. Indeed, the desensitization of NAADP-receptors prevented the onset of the fertilization potential. Taken together, these data suggest that NAADP could trigger the fertilization potential in starfish oocytes.

Original languageEnglish
Pages (from-to)515-524
Number of pages10
JournalCell Calcium
Issue number6
Publication statusPublished - 2004 Dec


  • Calcium
  • Fertilization
  • Oocyte
  • Starfish

ASJC Scopus subject areas

  • Physiology
  • Molecular Biology
  • Cell Biology


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