Effect of arabinosyl-cytosine on the G 1-arrested cells which were subsequently induced to divide by medium change

Abstract

Treatment of C3H2K cells arrested in the G 1 phase with arabinosyl-cytosine (araC) for 2 h caused an unexpected delay of DNA synthesis when the cells were subsequently induced to divide by medium change. The araC-induced delay was reversed by excess amount of deoxycytidine. The higher the concentration of araC, the longer the delay period. The delay period was invariable whether the cells were treated with araC from 0 to 2 h or from 6 to 8 h, i.e., early or late G 1. Similar delay was produced by ethidium bromide and fluorodeoxyuridine.