Aflatoxin B1-Associated DNA Adducts Stall S Phase and Stimulate Rad51 foci in Saccharomyces cerevisiae
Figure 1
Rad53 checkpoint activation, cell cycle progression, and recombination after log-phase cells were exposed to 50 μM AFB1. At indicated times, cells were collected for FACS analysis to measure frequencies of SCE and to make extracts to measure Rad53 activations. (a) Rad53 checkpoint activation was monitored after AFB1 exposure at the indicated times. Rad53 and the activated checkpoint protein, Rad53p, are indicated by arrows. (b) FACS analysis was performed at indicated time periods after exposure. The G1 and G2 cells are indicated by P4 and P5. The peak to the right of the G2 peak indicates bloated cells due to enlarged vacuoles. (c) AFB1-associated SCE were measured by selecting for His+ recombinants that result from unequal recombination between two truncated his3 fragments. Net recombination frequencies = recombination frequency after AFB1 exposure—spontaneous recombination frequency.
