Abstract
During mitosis, chromatin is condensed and organized into mitotic chromosomes. Condensation is critical for genome stability and dynamics, yet the degree of condensation is significantly different between multicellular and single-cell eukaryotes. What is less clear is whether there is a minimum degree of chromosome condensation in unicellular eukaryotes. Here, we exploited two-photon microscopy to analyze chromatin condensation in live and fixed cells, enabling studies of some organisms that are not readily amenable to genetic modification. This includes the yeasts Saccharomyces cerevisiae, Schizosaccharomyces pombe, Kluyveromyces lactis, and Candida albicans, as well as a protist Trypanosoma brucei. We found that mitotic chromosomes in this range of species are condensed about 1.5-fold relative to interphase chromatin. In addition, we used two-photon microscopy to reveal that chromatin reorganization in interphase human hepatoma cells infected by the hepatitis C virus is decondensed compared to uninfected cells, which correlates with the previously reported viral-induced changes in chromatin dynamics. This work demonstrates the power of two-photon microscopy to analyze chromatin in a broad range of cell types and conditions, including non-model single-cell eukaryotes. We suggest that similar condensation levels are an evolutionarily conserved property in unicellular eukaryotes and important for proper chromosome segregation. Furthermore, this provides new insights into the process of chromatin condensation during mitosis in unicellular organisms as well as the response of human cells to viral infection.
| Original language | English |
|---|---|
| Article number | 17393 |
| Journal | Scientific Reports |
| Volume | 12 |
| Issue number | 1 |
| DOIs | |
| State | Published - 17 Oct 2022 |
Bibliographical note
Publisher Copyright:© 2022, The Author(s).
Funding
Katreena Yamin performed this study as partial fulfillment of the requirements for a Ph.D. degree in the Azrieli Faculty of Medicine, Bar-Ilan University. We would like to thank Pascal Bernard for sharing S. pombe strains and productive discussions, Yehuda Tzfati for sharing K. lactis, Michael Assa for his technical support with microscopy, Basem Hijazi for his help with statistics, and K. Ganesan for providing the cassette to create pTETR-SMC2 strain. Thanks, too, to our editor, Steve Spencer. This work was supported by grants from the Israel Science Foundation, No. 987/19 (IO) and No. 1880/19 (JS), and a by a grant from the Israel Cancer Association, 20221266 (IO). Katreena Yamin performed this study as partial fulfillment of the requirements for a Ph.D. degree in the Azrieli Faculty of Medicine, Bar-Ilan University. We would like to thank Pascal Bernard for sharing S. pombe strains and productive discussions, Yehuda Tzfati for sharing K. lactis , Michael Assa for his technical support with microscopy, Basem Hijazi for his help with statistics, and K. Ganesan for providing the cassette to create pTETR-SMC2 strain. Thanks, too, to our editor, Steve Spencer. This work was supported by grants from the Israel Science Foundation, No. 987/19 (IO) and No. 1880/19 (JS), and a by a grant from the Israel Cancer Association, 20221266 (IO).
| Funders | Funder number |
|---|---|
| Azrieli Faculty of Medicine, Bar-Ilan University | |
| Israel Cancer Association | 20221266 |
| Israel Science Foundation | 1880/19, 987/19 |
