Abstract
Frequencies and distribution of chromatid breaks (CBs) and sister chromatid exchanges (SCEs) induced by hydroxyurea (HU) were examined in Chinese hamster D-6 and lung primary cultured cells. About 30 to 50% of regions in CBs occurring by HU associated with those of the SCEs. Association of CBs and SCEs was examined by other chemicals such as BrdU, FdU, dA, dG, and Dt, which induced both SCEs and CBs. The association rate was obtained at about 20 to 50% by them. A highly associating region (about 80%) was found on X chromosome of D-6 cells, but it was not found in the lung cultured cells. Such association of SCEs and CBs was discussed in relation to the Revell's hypothesis.
