Chromatin loop size in human leukemia (HL-60) cells.
Human leukemia (HL-60) cells were treated with 0.1% detergent Joy and chromatin, protruded from the cell, was observed with an electron microscope. It was demonstrated that most, but not all of the protruded chromatin fibers had a loop structure. The average length of the protrusions of chromatin from the nucleus was 8.47 microns. A high magnification revealed that most of the protruded chromatin consisted of beaded nucleosomal fibers. Therefore, the chromatin loop size was estimated to be 315 +/- 47 k base pairs in length. This length is much longer than that of the fragmented DNA seen in the apoptosis of HL-60 cell, conflicting with the hypothesis that the DNA fragmentation is related to the size of the chromatin loop.
Tohno
Y
Y
Department of Anatomy, Nara Medical University, Japan.
Tohno
S
S
Tanaka
Y
Y
D002843:Chromatin / Q000737:chemistry / Q000648:ultrastructure*; D004273:DNA, Neoplasm / Q000032:analysis / Q000648:ultrastructure; D006801:Humans; D015473:Leukemia, Promyelocytic, Acute / Q000473:pathology*; D008854:Microscopy, Electron / Q000379:methods*; D014407:Tumor Cells, Cultured
D002843:Chromatin; D004273:DNA, Neoplasm