高等生物体内含有多种多样的细胞,但归根到底,皆由一个受精卵分化而来;在不同的环境条件下,同一细胞还可处于多种不同的功能状态。同一个体的各细胞所含染色质的DNA基本相同,其形态功能的差别,关键在于染色质有不同的表达。细胞内外有多种因素可以影响DNA上的转录过程,探讨这些因素对转录的调控作用是研究基因表达机 Higher organisms contain a variety of cells, but in the final analysis, all from a fertilized egg differentiation; under different environmental conditions, the same cell can also be in a variety of different functional status. The same individual cells contain chromatin DNA is basically the same, the difference of its morphological function, the key lies in the chromatin have different expression. A variety of factors inside and outside the cell can affect the transcriptional process on DNA, and to explore the regulatory role of these factors on transcription is to study gene expression machinery