Fig 4.

TBZ sensitivity in brc1Δ cells. (A) TBZ sensitivity caused by brc1Δ is additive to that caused by swi6Δ. Tenfold serial dilutions were incubated at 30°C for 2 days. (B) Mitotic abnormalities in brc1Δ cells released from a cdc25-22 arrest in the absence or presence of 5 μg/ml TBZ. Micrographs were taken at 60 min after release from the arrest. DNA was stained with DAPI and antitubulin antibody (TAT1). The arrow points to a lagging chromosome (or chromosome fragment) in brc1Δ cells treated with TBZ.