ABSTRACT Exposure to low temperature prior to insemination increases the likelihood of polyspermy in Lytechinus variegatus eggs. Electrophysiological recordings reveal that cold shock partially disrupts the egg's action potential, producing a subthreshold depolarization during the fertilization response. This attenuated shift in membrane potential appears insufficient to activate the fast block to polyspermy, allowing entry of multiple sperm. These findings identify a temperature‐sensitive vulnerability in the electrical barrier to polyspermy in sea urchin eggs.
Ivonnet et al. (Thu,) studied this question.