Propranolol induces polyspermy during sea urchin fertilization

Area of Science:

• Marine Biology
• Developmental Biology
• Pharmacology

Background:

• Sea urchin eggs are a model system for studying fertilization.
• The cortical reaction is crucial for preventing polyspermy.
• Monoaminergic systems are implicated in various biological processes, including fertilization.

Purpose of the Study:

• To investigate the effect of propranolol on sea urchin egg fertilization.
• To determine if propranolol induces polyspermy.
• To elucidate the mechanism underlying propranolol-induced fertilization defects.

Main Methods:

• Treatment of unfertilized sea urchin eggs with propranolol.
• Insemination of treated eggs.
• Light, transmission, and scanning electron microscopy to examine egg structure and cortical reaction.
• Assessment of fertilization envelope formation and polyspermy.

Main Results:

• Propranolol treatment (50 microM) induced polyspermy in sea urchin eggs.
• A defective and incomplete cortical reaction was observed post-insemination.
• The fertilization envelope showed abnormal, minimal elevation.
• Electron microscopy revealed no alterations to the unfertilized egg cortex.

Conclusions:

• Propranolol interferes with the sea urchin egg cortical reaction, leading to polyspermy and defective fertilization envelope formation.
• The findings suggest propranolol's action may involve the monoaminergic system.
• Adrenalin reversed propranolol's effects, supporting its interaction with the monoaminergic system during fertilization.