Dale B
Stazione Zoologica, Naples, Italy.
Exp Cell Res. 1988 Jul;177(1):205-11. doi: 10.1016/0014-4827(88)90038-9.
Two early events of activation in the ascidian egg, the surface contraction and the fertilization current, were studied. Ca ionophore induces contraction without generating a fertilization current, whereas microinjection of IP3 or soluble fractions of homogenized spermatozoa trigger both a contraction and a current. This suggests that the primary trigger of activation in ascidian eggs is a soluble component of spermatozoa that may be released into the egg subsequent to gamete fusion. IP3, or other intermediates in phosphoinositide metabolism, is a putative second messenger that activates fertilization channels directly (probably a Ca-independent process), and subsequently induces surface contraction by releasing Ca from intracellular stores.
对海鞘卵激活的两个早期事件，即表面收缩和受精电流进行了研究。钙离子载体诱导收缩但不产生受精电流，而显微注射肌醇三磷酸（IP3）或匀浆精子的可溶性组分则会引发收缩和电流。这表明海鞘卵激活的主要触发因素是精子的一种可溶性成分，它可能在配子融合后释放到卵中。IP3或磷酸肌醇代谢中的其他中间体是一种假定的第二信使，它直接激活受精通道（可能是一个不依赖钙的过程），随后通过从细胞内储存中释放钙来诱导表面收缩。
