Figure 2.

Colocalization of extrachromosomal HMR circles produced by the M and G1 excision protocols. (A) Simple HMR circles were generated in strains RDY143 (SIR3) and RDY189 (Δsir3). N indicates number of cells examined. (B) Extended HMR circles were generated in strains RDY152 (SIR3) and RDY151 (Δsir3). (C) Cohesion of extended HMR circles requires MCD1/SCC1. Strains RDY152 (SCC1) and RDY213 (scc1-73) were subjected to the G1 excision protocol. Cells were grown at 24°C until 1 h after removal of α-factor, when the cultures were shifted to 37°C for 2 h. The temperature shift increases cohesion in the wild-type strain (cf. B and C).