| First Author | Fukami K | Year | 2003 |
| Journal | J Cell Biol | Volume | 161 |
| Issue | 1 | Pages | 79-88 |
| PubMed ID | 12695499 | Mgi Jnum | J:82910 |
| Mgi Id | MGI:2655986 | Doi | 10.1083/jcb.200210057 |
| Citation | Fukami K, et al. (2003) Phospholipase Cdelta4 is required for Ca2+ mobilization essential for acrosome reaction in sperm. J Cell Biol 161(1):79-88 |
| abstractText | 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 PLCdelta4 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 PLCdelta4-/- sperm. Progesterone, another physiological inducer of the acrosome reaction, failed to induce sustained [Ca2+]i increases in PLCdelta4-/- 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 PLCdelta4-/- sperm. These results indicate that PLCdelta4 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. |
