关于分子生物学的,这句话怎么翻译,急!

题目

关于分子生物学的,这句话怎么翻译,急!
While missense mutations can, in principle, be reverted either by a true reversion event or by a second site event,two noteworthy reversion systems have been developed that are based on an absolutely invariant amino acid in either the Cyc1 or Trp5 protein.求翻译,关键是 event 在这里是什么意思?

答案

虽然错义突变在理论上可以回复,要么通过在原突变位点的回复突变（真回复突变）要么通过在第二的位点的突变.但值得注意的是这两种回复突变体系已经发展,是建立在要求有一个绝对不变的氨基酸,无论在Cyc1或Trp5蛋白质中.
我想event在这应该是指回复突变