Zas1 localization to chromosomes is essential for its function. (A) Schematic representation of the zas1 gene locus. The positions of a NLS (green), of the C₂H₂ ZF DNA binding motifs (dark blue), of a predicted fungal TF domain (fungal_trans, yellow), of a noncoding antisense RNA transcript, and of ts mutations and their effect on the Zas1 protein (with X representing a stop codon) are indicated. Lines represent noncoding introns. (B) Tetrad analysis of a heterozygous zas1-tdTomato/zas1⁺ diploid fission yeast strain (C5091) after 5 d at 25°C. Circles identify the position of spores bearing the zas1-tdTomato gene. (C) Example images of Zas1-tdTomato localization (left) and chromatin staining with Hoechst (right; strain C3782). (D) Tetrad analysis of heterozygous Δzas1/zas1⁺, zas1^c/zas1⁺, zas1^c-Δ9–17/zas1⁺, and zas1c-Δ25–83/zas1⁺ diploid fission yeast strains (C4005, C4083, C4470, and C4093) after 5 d at 25°C. Circles identify the position of spores bearing the Δzas1, zas1^c, zas1^c-Δ9–17, or zas1c-Δ25–83 genes, respectively.