A transcriptionally active monkey genomic segment homologous to the regulatory region of simian virus 40 is associated with DNase I-hypersensitive sites.

Segments of monkey genomic DNA that are homologous to the control region around the origin of replication of simian virus 40 were previously cloned and characterized (Queen et al., Mol. Cell Biol. 1:1061-1068, 1981). We describe here two DNase I-hypersensitive sites that map in the region of monkey chromatin around one such ori-like segment. One of these sites lies within the simian virus 40 homologous segment which is also a site from which transcription initiates bidirectionally (J. Saffer and M. Singer, submitted for publication).