Fleischmann, G., Pflugfelder, G.O., Steiner, E.K., Javaherian, K., Howard, G.C., Wang, J.C., Elgin, S.C. (1984). Drosophila DNA topoisomerase I is associated with transcriptionally active regions of the genome.  Proc. Natl. Acad. Sci. U.S.A. 81(): 6958--6962.

FBrf0041677

Research paper

The distribution of DNA topoisomerase I within Drosophila polytene chromosomes was observed by immunofluorescent staining with affinity-purified antibodies. The enzyme is preferentially associated with active loci, as shown by prominent staining of puffs. The heat shock loci 87A-87C are stained after, but not before, heat shock induction. A detailed comparison of the distribution of topoisomerase I with that of RNA polymerase II reveals a similar, although not identical, pattern of association. Topoisomerase I is also found in association with the nucleolus, the site of transcription by RNA polymerase I.

PMC392055 (PMC) (EuropePMC)