Abstract
The numbers of single-strand breaks and their rates of rejoining have been compared in two Yoshida cell-lines showing similar sensitivity to X-rays (D0 85 rads, n = 2·5) and two L5178Y cell-lines showing differential sensitivity; the sensitive cell-line having a D0 value of 55 rads, n = 2·5, and the resistant line a D0 value of 160 rads and n = 3·0. After doses of 5 or 10 krads, no differences in the numbers of single-strand breaks produced or in their rates of rejoining were observed when measured by the alkaline sucrose gradient technique. The findings confirm that single-strand breaks in themselves are not lethal events, since similar numbers are produced and virtually all are rejoined in the cell-lines studied. However, a deficiency in some of the processes involved in repair replication could be the cause of their differential sensitivity by allowing damage to be fixed.

This publication has 19 references indexed in Scilit: