Fixed or live imaging data on spatial distributions of homologous centromeres labeled by specific FISH probes (for fixed imaging) or dCas9-EGFP with specific sgRNA (for live and fixed imaging). In dCas9-EGFP images, chromosomes and the centrosomes were also marked using H2B-mCherry and EGFP-GCP3, respectively. In som experiments, chromosomes and the centrosomes were fixed-stained with DAPI and anti-Cep192 antibody, respectively. Images show the distributions of labeled centromeres at different mitotic stages during the first mitosis after whole-genome duplication. dCas9-EGFP and EGFP-GCP3 signals are distinguished based on their location relative to mitotic chromosomes (dCas9-EGFP signals are on the chromosomes, while EGFP-GCP3 signals are out of the chromosome area). Anaphase/telophase images were used to analyze the frequency of nullisomic chromosome segregation (where certain segregated chromosome masses contain no homologous centromere signals), which differed depending on the types of whole-genome duplication occurring prior to the observed mitosis.
See details in Inoko et. al. (2025) bioRxiv.
Masaya Inoko, Guang Yang, Yuki Tsukada, Ryota Uehara (2026) Sister chromatid separation determines the proliferative properties upon whole-genome duplication via homologous chromosome arrangement., Proceedings of the National Academy of Sciences of the United States of America, Volume 123, Number 16, pp. e2524135123
Published in 2026 Apr 21 (Electronic publication in April 15, 2026, midnight )
(Abstract) Whole-genome duplication (WGD) of diploid cells triggers various cell fates, such as cell death, cell cycle arrest, and proliferation with chromosome instability, contributing to broad bioprocesses, including differentiation, tumorigenesis, or aging. However, factors determining the post-WGD cell fates remain largely unknown. In this study, we found that cytokinesis failure (CF) and mitotic slippage (MS), two major routes of WGD induction, differentially affected post-WGD viability and proliferation in human cells. Quantitative live imaging revealed poorer survivability of cells upon multipolar chromosome segregation at the first mitosis after MS than CF. Chromosome-specific labeling showed that the inefficient sister chromatid separation upon MS caused more skewed homologous chromosome distribution than CF. The skewed homologue distribution frequently led to physical isolation (>10 mum) of the centrosomes from all homologous centromeres, hindering these centrosomes from capturing any of these homologues. The difference in the frequency of this nullisomic chromosome segregation between MS and CF at least partially explained their difference in the viability of the subsequent daughter cells. Moreover, artificial separation of sister chromatids upon MS improved the evenness of homologue distribution, suppressed nullisomic homologue segregation in the following mitosis, and significantly restored the viability of their daughter cells. These results demonstrate the geometric arrangement of homologous chromosomes, defined by the presence or absence of sufficient sister chromatid separation upon WGD, as a key factor determining the proliferative characteristics of subsequent progenies. Our findings would provide a clue to understanding the route-dependent outcomes of WGD in cell fate determination in different bioprocesses.(MeSH Terms)
Inoko, Masaya, Yang, Guang, Tsukada, Yuki, Uehara, Ryota (2025/01/01), Sister chromatid separation determines the proliferative characteristics upon whole-genome duplication through homologous chromosome rearrangement, bioRxiv, 2025.08.27.672736
Published in 2025/01/01
(Abstract) None