Complex Genetic Organization of junB: Multiple Blocks of Flanking Evolutionarily Conserved Sequence at the Murine and Human junB Loci

A comparison of the murine and human junB loci reveals nine regions of distal 5′- and 3′-flanking DNA that exhibit greater than 72% sequence identity. A large fraction (over 50%) of the junB locus is contained in these flanking evolutionarily conserved sequences (FECS), which may be required for effecting the proper transcriptional regulation of this gene. Comparative sequence analyses involving kilobases of distal flanking DNAs have been performed for only a small number of vertebrate genes. The available data and the results presented here suggest that FECS may emerge as common yet important functional components of genes, a hypothesis with significant implications for characterizing genes involved in human disease.