人基因组表现了广泛的多态性。由于单一碱基的改变或小片段的缺失和插入,产生或破坏了某一特定限制性内切酶的识别点,从而引起限制性片段长度的多态性(restriction fragment length polymorphisms,RFLPs)。另外,还有一种类型的RFLPs,即长度可变的多态性。这种多态性是串联重复序列中拷贝数目的差别造成的。最近有人报道了一种探针,此种探针以核心序列的串联重复序列为基础,可同时探查出许多 The human genome shows a wide range of polymorphisms. Restriction fragment length polymorphisms (RFLPs) are caused or destroyed by single base changes or deletion and insertion of small fragments, resulting in disruption of the recognition site of a particular restriction enzyme. In addition, there is another type of RFLPs, variable length polymorphisms. This polymorphism is caused by the difference in the number of copies in tandem repeats. Recently, it has been reported that a probe based on the tandem repeat sequence of the core sequence can simultaneously probe out many