(Po)STAC (Polycistronic SunTAg modified CRISPR) enables live-cell and fixed-cell super-resolution imaging of multiple genes
01 Dec 2019
Year of publication: 2018
Journal: Nucleic Acids Research
Content: Super Resolution Data repository (click to request access to raw data):
06 Apr 2016
Super-resolution microscopes reveal the link between genome packaging and cell pluripotency
Nucleosomes help structure chromosomes by compacting DNA into fibers. To gain insight into how nucleosomes are arranged in vivo, we combined quantitative super-resolution nanoscopy with computer simulations to visualize and count nucleosomes along the chromatin fiber in single nuclei. Nucleosomes assembled in heterogeneous groups of varying sizes, here termed “clutches,” and these were interspersed with nucleosome-depleted regions. The median number of nucleosomes inside clutches and their compaction defined as nucleosome density were cell-type-specific. Ground-state pluripotent stem cells had, on average, less dense clutches containing fewer nucleosomes and clutch size strongly correlated with the pluripotency potential of induced pluripotent stem cells. RNA polymerase II preferentially associated with the smallest clutches while linker histone H1 and heterochromatin were enriched in the largest ones. Our results reveal how the chromatin fiber is formed at nanoscale level and link chromatin fiber architecture to stem cell state.