Figure 6.

Depolarization triggers membrane retrieval by opening agatoxin-sensitive channels. Eggs were fertilized and placed into CF-ASW 3 minutes after fertilization. Ten minutes after fertilization, the eggs were placed into CF-ASW containing 100 μM TMR-Dex and supplemented with 9.3 mM CaCl₂ (+Ca), 50 mM KCl (+K), 9.3 mM CaCl₂ + 50 mM KCl (+Ca +K), or 9.3 mM CaCl₂ + 50 mM KCl + 50 nM agatoxin TK (+Ca +K +AgaTK). The amount of subsequent membrane retrieval was assayed 15 minutes after the addition of tetramethylrhodamine (t = 25 min). All points are normalized to TMR-Dex uptake in sperm-activated eggs in ASW (between t = 3 and 18 minutes) represents 100% retrieval, and TMR-Dex uptake in sperm-activated eggs in CF-ASW (between t = 3 and 18 minutes) represents 0% retrieval. All data points are mean ± SD n = 6.