FIGURE 7:

smc3-RQ allele–bearing smc3-42 cells and eco1Δ wpl1Δ cells promote chromosome condensation at the rDNA locus. (A–C) Haploid strains from Figure 2A, smc3-42 parent alone (smc3) or containing a second SMC3 allele, WT, K113Q, or RQ, were synchronously arrested in mid M phase at 35.5°C using nocodazole as described in Figure 2A. The rDNA resides in the nucleolus adjacent to the bulk chromosomal DNA. (A) Micrographs of WT and smc3-42 cells subjected to FISH. Bulk chromosomal DNA (DAPI) and rDNA detected using FISH (rDNA). Arrows indicate rDNA in DAPI-stained images. (B) Quantitation of rDNA condensation by scoring loop-like rDNA structure. (C) Micrographs of RQ allele in smc3-42 cells subjected to FISH. DAPI-stained bulk chromosomal DNA shown with arrows indicating rDNA. (D) WT and eco1Δ wpl1Δ cells from Figure 3A subjected to FISH as described in A and quantified as described in B. Data were derived from two independent experiments, and error bars are SD. For condensation assays, 50–150 nuclei were scored for each data point in each experiment.