ACTION OF RADIATION ON MAMMALIAN CELLS, IV. REVERSIBLE MITOTIC LAG IN THE S3 HELA CELL PRODUCED BY LOW DOSES OF X-RAYS

Abstract

The life cycle of hyperploid S3 HeLa cells, irradiated with sublethal doses of X-rays, has been studied. A reversible mitotic lag is demonstrable at doses of 34 to 135 rads, produced by a block localized in the G2, pre-mitotic period. Visible chromosomal aberrations are produced in a majority of the cell population at these doses. It is proposed that this reversible mitotic lag, like irreversible reproductive death, is due to chromosomal damage, and that the reversible lag may reflect interference with chromosomal condensation just prior to and perhaps in the early parts of mitosis.