Figure 4.

Template mutations lead to impaired chromosome separation and segregation. Strains bearing tlc1 template mutations contained Lac operator repeats integrated at the TRP1 locus near the centromere (yEHB5025-derived) or near the telomere (yEHB5026-derived). Template mutations were well-established at telomeres before cytological analysis (six passages, ∼120 generations). (A) Classes 1–7 show all spot-conformations that were observed during microscopic analysis in either cen- or telmarked strains. Sister chromatid separation and sister chromatid segregation were scored as indicated. (B) Distribution of marked chromosomes at representative time point, t = 100, for Wt cen; top2-4cen and top2-4tel; tlc1cen mutants (D) (E), and (SS); cdc13-1cen at 30°C and 23°C; cdc13-5cen; cdc13-1cen in combination with Δddc1, Δddc2, or both at 23°C and Δmad2 alone or in combination with tlc1cen (D).