help button home button Biophys. J.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS

Biophysical Journal 11: 540-549 (1971)
© 1971 the Biophysical Society

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Han, A.
Right arrow Articles by Yu, C. K.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Han, A.
Right arrow Articles by Yu, C. K.

Ultraviolet Light-Induced Division Delay in Synchronized Chinese Hamster Cells

Antun Han, Warren K. Sinclair and C. K. Yu

ABSTRACT

The age-dependent, ultraviolet light (UVL) (254 nm)-induced division delay of surviving and nonsurviving Chinese hamster cells was studied. The response was examined after UVL exposures adjusted to yield approximately the same survival levels at different stages of the cell cycle, 60% or 30% survival. Cells irradiated in the middle of S suffered the longest division delay, and cells exposed in mitosis or in G1 had about the same smaller delay in division. Cells irradiated in G2, however, were not delayed at either survival level. It was further established, after exposures that yielded about 30% survivors at various stages of the cycle, that surviving cells had shorter delays than nonsurvivors. This difference was not observed for cells in G2 at the time of exposure; i.e., neither surviving nor nonsurviving G2 cells were delayed in division. The examination of mitotic index vs. time revealed that most cells reach mitosis, but all of the increase in the number of cells in the population can be accounted for by the increase of the viable cell fraction. These observations suggest strongly that nonsurviving cells, although present during most of the experiment, are stopped at mitosis and do not divide. Cells in mitosis at the time of irradiation complete their division, and in the same length of time as unirradiated controls. Division and mitotic delays after UVL are relatively much larger than after X-ray doses that reduce survival to about the same level.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1971 by the Biophysical Society.