This chapter discusses the relative merits of the basic approaches to assay tissue-specific gene expression. A comparison between the albumin-α-fetoprotein (AFP) and β-globin gene families is made in terms of the possible functions for linkage and coordinated gene activity. Transgenic mice is used to map the regions required for the transcriptional inactivation of AFP. To determine whether developmental regulation results from stage-specific enhancers, the capacity of the AFP enhancers is tested to direct the expression of albumin. In three separate lines of transgenic mice, expression in fetal livers was high, and this level persisted into adulthood. In contrast, an AFP gene activated by the albumin enhancer was repressed after birth. These results prove that the enhancer domain is not sufficient to direct the developmental program of AFP; that is, the enhancers themselves are not stage-specific. The transcriptiona1 decline after birth is mediated by the proximal 1 kb of 5’-flanking DNA, or intragenic sequences. It has been the albumin and AFP genes contain a number of regulatory sequences important for their expression.
|Original language||English (US)|
|Number of pages||13|
|Journal||Progress in Nucleic Acid Research and Molecular Biology|
|State||Published - Jan 1 1989|
All Science Journal Classification (ASJC) codes
- Molecular Biology