Phospholipase Cδ4 is required for Ca2+ mobilization essential for acrosome reaction in sperm

Kiyoko Fukami*, Manabu Yoshida, Takafumi Inoue, Manabu Kurokawa, Rafael A. Fissore, Nobuaki Yoshida, Katsuhiko Mikoshiba, Tadaomi Takenawa

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

139 Citations (Scopus)


Zona pellucida (ZP)-induced acrosome reaction in sperm is a required step for mammalian fertilization. However, the precise mechanism of the acrosome reaction remains unclear. We previously reported that PLCδ4 is involved in the ZP-induced acrosome reaction in mouse sperm. Here we have monitored Ca2+, responses in single sperm, and we report that the [Ca2+]i increase in response to ZP, which is essential for driving the acrosome reaction in vivo, is absent in PLCδ4-/- sperm. Progesterone, another physiological inducer of the acrosome reaction, failed to induce sustained [Ca2+]i increases in PLCδ4-/- sperm, and consequently the acrosome reaction was partially inhibited. In addition, we observed oscillatory [Ca2+]i increases in wild-type sperm in response to these acrosome inducers. Calcium imaging studies revealed that the [Ca2+]i increases induced by exposure to ZP and progesterone started at different sites within the sperm head, indicating that these agonists induce the acrosome reaction via different Ca2+ mechanisms. Furthermore, store-operated channel (SOC) activity was severely impaired in PLCδ4-/- sperm. These results indicate that PLCδ4 is an important enzyme for intracellular [Ca2+]i mobilization in the ZP-induced acrosome reaction and for sustained [Ca2+]i increases through SOC induced by ZP and progesterone in sperm.

Original languageEnglish
Pages (from-to)79-88
Number of pages10
JournalJournal of Cell Biology
Issue number1
Publication statusPublished - 2003 Apr 14
Externally publishedYes


  • Acrosome reaction
  • Calcium
  • Phospholipase C
  • Sperm
  • Zona pellucida

ASJC Scopus subject areas

  • Cell Biology


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