Supplementary Figure 5: Meiocytes deficient in pericentromeric heterochromatin formation show centromere assembly defects.

(A) Genetic epistasis analysis of mutations that abolish the bouquet or compromise heterochromatin assembly. Cumulative frequencies of non-attachment events in MI and MII are observed via GFP-Atb2, Sid4-GFP and Hht1-mRFP (as in Fig. 1). Asterisks indicate that all mutant backgrounds differ significantly from wt; no significant difference is observed among the various mutant genotypes. Number of cells filmed is indicated above each bar. Significance was calculated using Fisher’s exact test (wt-bqt1Δ p = 5 × 10⁻⁵, wt-clr4Δ p = 0.002, wt-clr4Δ bqt1Δ p = 0.0005, wt-dcr1Δ p = 0.01, wt-dcr1Δ bqt1Δ p = 0.0001, see Methods for details). (B) Series of frames of a film of a cell undergoing meiosis. Cnp1, tubulin and chromatin are observed via ectopically expressed Cnp1-GFP (green) atb2-mCherry (red) and Hht1-CFP (blue), respectively. Numbers below frames represent minutes before or after metaphase I. Scale bars represent 5 μm. This film shows an example of clr4Δ meiosis. Some chromosomes (arrows) fail to recruit cohesin and thus missegregate, while maintaining high levels of Cnp1.