Abstract
The suppression by protein synthesis inhibitors of chemically or physically induced sister chromatid exchanges (SCEs) in the euchromatin and heterochromatin of individual chromosomes, as well as in each cell cycle phase, were analyzed for Chinese hamster cells. Suppression in the euchromatin was more prominent than in the heterochromatin, and depended on the agents and chromosomes involved. Cell cycle studies demonstrated the dependence of this effect on DNA replication. The relationships among sister chromatid exchange, cycloheximide-suppression and DNA replication are also discussed here.