RT Journal Article SR Electronic T1 Macromolecular and biochemical changes of G0 fission yeast nuclei JF bioRxiv FD Cold Spring Harbor Laboratory SP 2020.01.11.899559 DO 10.1101/2020.01.11.899559 A1 Cai, Shujun A1 Tan, Zhi Yang A1 Nie, Xin A1 Shi, Jian A1 Gan, Lu YR 2020 UL http://biorxiv.org/content/early/2020/01/11/2020.01.11.899559.abstract AB Cells change their cytology in response to environmental cues and stress. Notably, large changes in nuclear architecture are accompanied by transcriptional reprogramming. When starved of nitrogen, Schizosaccharomyces pombe cells become rounder and they enter a quiescent “G0” state. These cells have smaller nuclei and undergo near-global transcriptional repression. Here we use electron cryotomography (cryo-ET) and cell-biology approaches to investigate the structural and biochemical changes of G0 S. pombe nuclei. We find that G0 cells have a denser nucleoplasm and fewer chromatin-associated multi-megadalton globular complexes (megacomplexes) than proliferating cells. These structural changes are correlated with mild histone deacetylation. Induced histone hyperacetylation in G0 results in cells that have larger nuclei and less condensed chromatin. However, these histone-hyperacetylated G0 cells still have repressed transcription, few megacomplexes, and a dense nucleoplasm. Like in budding yeast, S. pombe G0 nuclear phenotypes are controlled by multiple biochemical factors.