posted on 2022-12-12, 11:25authored byYasutaka Kakui, Christopher Barrington, Yoshiharu Kusano, Rahul Thadani, Todd Fallesen, Toru Hirota, Frank Uhlmann
Mitotic chromosomes in different organisms adopt various dimensions. What defines these dimensions is scarcely understood. Here, we compare mitotic chromosomes in budding and fission yeasts harboring similarly sized genomes distributed among 16 or 3 chromosomes, respectively. Hi-C analyses and superresolution microscopy reveal that budding yeast chromosomes are characterized by shorter-ranging mitotic chromatin contacts and are thinner compared with the thicker fission yeast chromosomes that contain longer-ranging mitotic contacts. These distinctions persist even after budding yeast chromosomes are fused to form three fission-yeast-length entities, revealing a species-specific organizing principle. Species-specific widths correlate with the known binding site intervals of the chromosomal condensin complex. Unexpectedly, within each species, we find that longer chromosome arms are always thicker and harbor longer-ranging contacts, a trend that we also observe with human chromosomes. Arm length as a chromosome width determinant informs mitotic chromosome formation models.
Funding
Crick (Grant ID: 10198, Grant title: Uhlmann FC001198)
Crick (Grant ID: CC1069, Grant title: STP Light Microscopy)
Crick (Grant ID: CC1107, Grant title: STP Bioinformatics & Biostatistics)
European Research Council (Grant ID: 670412 - ChromatidCohesion, Grant title: ERC 670412 - ChromatidCohesion)