Jhd2 regulates chromosome condensation at the rDNA locus. (A) rDNA FISH was performed for WT, jhd2Δ or gis1Δ strains arrested at metaphase by treatment with nocodazole. Scale bar: 5 μm. (B) Quantitation of relative rDNA decondensation in (A). The area of the green rDNA FISH signal was divided by the area of the red propidium iodide signal and then normalized to the WT value. (C) rDNA FISH was performed for cells containing empty vector (pRS424), constructs expressing HA-tagged WT Jhd2, or the H427A mutant, which were grown in SC medium lacking Trp. (D) Quantitation of relative rDNA decondensation in (C). (E) Cells lacking or overexpressing Jhd2 used in (A) or (C) showing different rDNA morphologies (arrowhead, mislocalized and hypercondensed rDNA; double arrowhead, two bodies). (F) Quantitative analyses of rDNA morphology in cells used in (A) and (C). Percentages of cells with the indicated rDNA phenotype are shown. WT, wild type.