Distribution pattern of acridine orange chromatin interaction products in rat glioma C6 cells at different phases of the cell cycle.
The purpose of the present study was to examine the distribution pattern of electron-dense acridine orange (AO) chromatin interaction products in rat glioma C6 cells at different phases of the cell cycle. For synchronization in the early S-phase the cells in logarithmic growth were treated with 3 micrograms/ml aphidicolin, a specific inhibitor of DNA polymerase alpha and then cultured in normal medium. For synchronization in the M-phase the cells cultured with aphidicolin and then returned to normal medium were treated with 0.05 micrograms/ml colcemid. Histoautoradiographic analysis of the C6 cells using the pulse chase method demonstrated approximately 16 h of cell cycle time and about 6.5 h of S-phase. Ultracytochemically, AO chromatin interaction products were found in all phases of the cell cycle except for the mitotic phase, namely in G1, S, and G2. The highest percentage of AO chromatin interaction products was observed in the early S-phase and the lowest in the G2 phase. The mean number of AO chromatin interaction products per nuclear area increased in the course of S-phase parallel with an increase of 3H-uridine uptake during the S-phase. The results show a characteristic distribution pattern of AO label specific for each of the four stages of the cell cycle, however, the significance of the coincident RNA synthetic activity remains to be elucidated.
Department of Pathology, Kochi Medical School, Japan.
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H
Hara
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T
Moriki
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M
Hiroi
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S
Watanabe
T
T
Yamane
R
R
Lehmann
D000165:Acridine Orange; D000818:Animals; D016590:Aphidicolin; D001345:Autoradiography; D002453:Cell Cycle / Q000187:drug effects / Q000502:physiology; D002843:Chromatin / Q000032:analysis*; D004273:DNA, Neoplasm / Q000096:biosynthesis*; D003703:Demecolcine / Q000494:pharmacology; D004224:Diterpenes / Q000494:pharmacology; D005910:Glioma / Q000648:ultrastructure*; D008854:Microscopy, Electron; D051381:Rats; D013194:Staining and Labeling; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000648:ultrastructure
D002843:Chromatin; D004273:DNA, Neoplasm; D004224:Diterpenes; D016590:Aphidicolin; D000165:Acridine Orange; D003703:Demecolcine