Near millimolar concentration of nucleosomes in mitotic chromosomes from late prometaphase into anaphase.

ABSTRACT: Chromosome compaction is a key feature of mitosis and critical for accurate chromosome segregation. However, a precise quantitative analysis of chromosome geometry during mitotic progression is lacking. Here, we use volume electron microscopy to map, with nanometer precision, chromosomes from prometaphase through telophase in human RPE1 cells. During prometaphase, chromosomes acquire a smoother surface, their arms shorten, and the primary centromeric constriction is formed. The chromatin is progressively compacted, ultimately reaching a remarkable nucleosome concentration of over 750 µM in late prometaphase that remains relatively constant during metaphase and early anaphase. Surprisingly, chromosomes then increase their volume in late anaphase prior to deposition of the nuclear envelope.

SUBMITTER: Cisneros-Soberanis F 

PROVIDER: S-EPMC11346515 | biostudies-literature | 2024 Nov

REPOSITORIES: biostudies-literature