Fig. 1

Chromosome conformation during yeast meiosis. a Upper panel: cartoon of chromosome morphology during the stages analysed in the meiotic time course. The Rabl-structure observed in G1 is characterised by centromere clustering (in blue), meiotic axis proteins are represented in green, with the fully assembled synaptonemal complex (SC) represented in light green. Lower panels: cells were collected during meiosis at indicated timepoints and analysed by Hi-C. At 0 h the cells are in G1. Representative Hi–C contact maps of chromosomes 6, 11 and 7 plotted at 5 kb resolution. Centromeres, telomeres and arm fold-back at the centromere are indicated by blue, red and grey arrows, respectively, and axial compaction by the width of the main diagonal relative to the fixed-width black clamp. For interactive HiGlass¹ views see: http://higlass.pollard.gladstone.org/app/?config=Z5iwKpjzQpePCXXyvuYGeQ. b Meiotic entry assessed by FACS; at 4 h, the majority of cells show a 4C peak indicating completion of DNA replication. c Meiotic progression was monitored by quantification of nuclear divisions determined by DAPI staining. Around 4 h, cells start to undergo meiotic divisions I and II. The majority of cells undergo meiotic divisions between 4 h and 8 h, indicating the degree of heterogeneity within the cell population. Source data are provided as a Source Data file. d Upper panels: Average trans centromere–centromere contact maps. Lower panels: trans telomere–telomere contact maps. Right: ratio of cis to total contact frequency. e Intra-arm contact probability versus genomic distance, P(s), indicating the emergence (left) and disappearance (right) of chromosome arm compaction during meiosis. Shaded area bounded above and below by the two ndt80∆ 8 h replicates. f Meiosis was induced in ndt80∆ cells for 8 h and meiotic entry was checked by monitoring DNA replication by FACS. g ndt80∆ cells were grown for 8 h in sporulation media and analysed by Hi–C (left). Log2 ratio of ndt80∆ cells 8 h over G1 (right). Centromeres and telomeres are indicated by blue and red arrows, respectively, and axial compaction by a black clamp. h Left: contact probability of individual chromosome arms stratified by length. Right: contact probability stratified by the distance from the telomere