INSERM U.91, Hôpital Henri-Mondor, 51, avenue du Maréchal de Lattre-de-Tassigny, 94010 Créteil.
One of the primary goals of transcription factor research is the elucidation of the genetic networks regulated by a factor or by members of a family of closely related factors. The development of efficient methods for the isolation of direct target genes for transcription factors is necessary for the understanding of the way these factors mediate their biological effect. Here we describe several strategies that have been set up to identify target genes for transcription factors. Some indirect procedures relie on differential cDNA screening, using differential hybridization, substractive hybridization or differential display. Other strategies are based on the binding of transcription factors to their target in vitro or in vivo in native chromatin, allowing the identification of direct target sequences and the subsequent cloning of the corresponding genes. The different methods are discussed in terms of choice for a strategy and in function of data and tools available concerning the factor.