Fig. 1.

ROS levels are reduced in daughter cells in a Sir2p-dependent way after completion of cytokinesis. (A and B) The images show 10- to 12-generation-old WT mother cells stained with dihydrorhodamine, an indicator of hydrogen peroxide, before (A) and after (B) completing cytokinesis; the arrowhead indicates the daughter cell. (C and D) Quantification of superoxide (C) and hydrogen peroxide (D) levels in the mother (M) and daughter (D) while they are still attached (left) and after separation (right). WT (empty bars) and sir2Δ (filled bars) cells were analyzed. (E) Carbonyl levels determined by in situ staining of samples described in C. Values were normalized relative to the WT mother cell during cytokinesis, which was arbitrarily set to 1. Error bars represent the SD of the mean. (Scale bar, 5 μm.)