引言增强子(enhanccr)是一类短的、顺式作用的正调节DNA序列。它们位于基因旁侧顺序的远处,能极大地增强其邻近基因的转录速率。文献中也有称之为调变子(modu-lator)或激活子(activator)的。目前,从病毒到真核细胞都发现有增强子存在。一般说来,增强子具有如下共同的特点:1.它们仅以“顺式”(cis)方式作用于基因的启动子;2.在启动子的上游或下游都可起增强作用;3.对启动子来说它们正向或反向排列均有效; Introduction Enhancrs are a class of short, cis-acting, up-regulated DNA sequences. They are located remotely from the side of the gene and greatly enhance the transcription rate of their neighboring genes. The literature also calls modulators or activators. Currently, there are enhancers found from viruses to eukaryotes. In general, enhancers have the following common features: 1. They act on the promoter of a gene only in a “cis” manner; 2. Enhance the effect either upstream or downstream of a promoter; 3. Pair Promoters are positively or inversely aligned for their effectiveness;