Melittin, a Component of Bee Venom, Activates Unfertilized Sea Urchin Eggs. (melittin/activation/sea urchin egg)

Melittin, which is known to stimulate phospholipase A, in many cells, caused as much elevation of fertilization membranes and increase in respiration of unfertilized eggs of the sea urchins Anthocidaris crassispina and Hemicentrotus pulcherrimus as normal fertilization. In melittin-activated eggs, amino acid transport was decreased to less than that of unfertilized eggs, nucleoside transport was only slightly, activated, protein synthesis was rather inhibited and neither DNA synthesis nor cleavage was observed. It is concluded that although melittin induces the cortical reaction and activation of respiration in unfertilized eggs, its cytotoxicity prevents any "late changes".