DNA‐synthesizing cells in oral epithelium have a range of cell cycle durations: evidence from double‐labelling studies using tritiated thymidine and bromodeoxyuridine
1989; Wiley; Volume: 22; Issue: 5 Linguagem: Inglês
10.1111/j.1365-2184.1989.tb00222.x
ISSN1365-2184
Autores Tópico(s)RNA and protein synthesis mechanisms
ResumoAbstract Mouse tongue epithelium is characterized by a circadian variation in the number of DNA‐synthesizing cells (labelling index, LI). Cells undergoing DNA synthesis were labelled with tritiated thymidine ([ 3 H]TdR) at 0300 (peak LI) or 1200 h (low LI). The fate of these cells was assessed by injecting animals with bromodeoxyuridine (BrdU) at intervals from 12–48 h after [ 3 H]TdR, to follow them from one cell cycle to the next. Labelling was revealed by combining [ 3 H]TdR autoradiography with immunoperoxidase detection of BrdU in the same sections. A single peak in the appearance of double‐labelled cells was seen at 44 h, if [ 3 H]TdR was given at 1200 h; following [3H]TdR at 0300 h, a peak of double labelling was seen at 48 h with the possibility of smaller peaks at 24 h and 36 h. These results show that the 24 h periodicity in LI in this tissue is associated with a predominant cell cycle duration of 44–48 h, but that a few cells cycle more quickly. Double labelling with [ 3 H]TdR and BrdU provides a useful method for establishing cell cycle duration by labelling S‐phase cells in successive cell cycles.
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