What Happens when Sperm Meets Egg: A Revisitation of the Process with star fish and sea urchins MASTS webinar with Luigia Santella (Stazione Zoologica Anton Dohrn, Italy) - free

Much of the knowledge on the fertilization process comes from research on sea urchin and starfish eggs that are fertilized in seawater. Even if starfish and sea urchin eggs are physiologically ripe for fertilization at different meiotic stages, their initial response to fertilizing sperm includes virtually the same structural and biochemical changes, i.e., separation of the vitelline layer from the egg plasma membrane and an intracellular calcium increase. Studies from our laboratory have shown that these sperm-induced changes strongly depend on the structural organization of F-actin of the egg cortex, which undergoes restructuration upon sperm-egg interaction. Furthermore, the F-actin remodeling plays a crucial role in preventing the entry of multiple sperm and in ensuring successful embryonic development