Identification and characterization of transcription factor target genes using gene-targeted mice

Critical to understanding biological roles for transcription factors is an appreciation of the target genes regulated by the transcription factor. The identification of target genes can often expand the understanding of known biological roles for a transcription factor and may reveal unappreciated and unexpected functions. This article focuses on the identification and characterization of transcription factor target genes using mouse molecular genetics. The use of genetically engineered (knockout) mice and global ! gone expression analysis to identify transcription factor target genes is reviewed, with emphasis on important technical considerations. Detailed protocols for the application of real-time reverse transcription polymerase chain reaction and immunohistochemistry in target gene expression analysis are described. The article closes with a discussion of the use of mouse molecular genetics for the characterization of target genes as downstream effectors of transcription factors. (C) 2002 Elsevier Science (USA). All rights reserved.