title: Additional DNA long-range folding is an early process during stimulation of human lymphocytes.
abstract: There is disagreement about the existence of permanent single-strand breaks in the nuclear DNA of quiescent lymphocytes, possibly due to different experimental approaches. Using the nucleoid sedimentation technique, no evidence is found for spontaneous DNA single-strand breakage in unstimulated human lymphocytes and for quick break-sealing after mitogenic stimulation. An increased sedimentation rate of nucleoids, which can be monitored as soon as 3 h after stimulation, is shown to be due rather to an additional long-range folding of nuclear DNA. Such temporal folding appears to be related to RNA transcription and may interfere with detection of DNA single-strand breakage.
authors.affiliation: Central Institute of Molecular Biology, Academy of Sciences of the German Democratic Republic, Berlin.
authors.forename: M
authors.initials: M
authors.lastname: Hartwig
mesh_terms: D002499:Centrifugation, Density Gradient; D004247:DNA; D004277:DNA, Single-Stranded; D004278:DNA, Superhelical; D006801:Humans; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000032:analysis* / Q000378:metabolism; D009690:Nucleic Acid Conformation; D014158:Transcription, Genetic
chemical_list: D004277:DNA, Single-Stranded; D004278:DNA, Superhelical; D004247:DNA