Biochem. Bio- phys
- O. V. Kretova, N. A. Tchurikov, Dokl
- vol. 403,
217 In recent years, convincing evidences have been presented demonstrating that eukaryotic chromosomes contain extended regions in which regulation of gene transcription is coordinated—gene expression is switched on or off. Such chromosomal regions are called transcriptional territories . The latter were discovered using the microarray technique. Earlier, fractionation of large DNA fragments made it possible to detect forum domains—DNA regions 50to 150-kb in length that are silencing or active transcription units [2– 4]. The boundaries of forum domains contain the socalled PRE/TRE sequences, which bind protein complexes that ensure repression (chromosomal silencing) or activation of transcription. These data were corroborated later in a study of the pattern of PRE sequences in Drosophila genome, in which 50to 150-kb domains, PcG domains, were found . Apparently, the transcriptional territories are the forum domains or PcG domains. However, the properties of sequences that make it possible to simultaneously switch on or off transcription at large distances from the boundaries of forum domains have not been characterized thus far.