Novel Ca2+ increases in the maturing oocytes of starfish during the germinal vesicle breakdown

- At meiotic reinitiation, starfish oocytes display an extraordinarily fast Ca2+ wave.
- A novel Ca2+ response was discovered at the time of nuclear membrane breakdown.
- This late response in the maturing oocytes comprises a train of Ca2+ spikes.
- The late Ca2+ spikes represent the Ca2+ influx via L-type channels.
- Latrunculin represses frequency of the Ca2+ spikes, but increases their amplitude.