Retention of labelled DNA precursor by murine cells after a single administration of tritium labelled thymidine.
The central zone of the rat lens epithelium, extending half way from the centre to the periphery of a whole mount preparation, normally has less than 1% of the cells in the cell cycle at any given time. Mechanical wounding initiates a burst of proliferation in the central zone. DNA synthesis begins 14 hr after wounding followed by mitosis 10 hr later. When [3H]TdR was applied at 2 hr prior to S phase, some moderately heavy and some light labelling was observed after the onset of S phase. When [3H]TdR was applied 5 hr before S phase (9 hr after wounding), all the cells were lightly labelled. Only small amounts of the label were available to these cells 5 hr after application. It is significant that there was labelling in this group because it indicates the persistence of relatively small intracellular pools of [3H]TdR for several hours after the initial 'pulse' labelling of cells. Determinations of the duration of S phase were based on the assumption that pulse labelling may be affected by the persistence of the pools of [3H]TdR and consequent light labelling of the cells.
D000818:Animals; D001345:Autoradiography; D002455:Cell Division; D046508:Culture Techniques; D004247:DNA / Q000096:biosynthesis*; D004847:Epithelial Cells; D007908:Lens, Crystalline / Q000166:cytology; D008938:Mitosis; D051381:Rats; D013936:Thymidine / Q000378:metabolism*; D013997:Time Factors; D014945:Wound Healing
D004247:DNA; D013936:Thymidine