Related Experiment Video
Updated: Sep 15, 2025

Author Spotlight: High-Throughput Image-Based Quantification of Mitochondrial DNA Synthesis and Distribution
Published on: May 5, 2023
Cell cycle- and dose-dependent effects on mitochondrial DNA copy number variation following irradiation
Ryosuke Seino1, Kai Nishikubo1, Hisanori Fukunaga1
1Department of Biomedical Science and Engineering, Faculty of Health Sciences, Hokkaido University, Sapporo 060-0812, Japan.
Abstract:
Cell survival after irradiation depends on the cell cycle at the time of exposure. This has been thought to be due to cell cycle-dependent nuclear DNA damage repair mechanisms. Here, we show the relationships between the exposed dose, the cell cycle phase at the time of exposure and changes in mitochondrial DNA copy numbers (mtDNAcn) after irradiation. We used a fluorescent ubiquitylation-based cell cycle indicator (FUCCI), which allows visualization of the cell cycle, and confirmed cell cycle synchronization in human cervical HeLa cells. In synchronous HeLa-FUCCI cells, the mtDNAcn changed with the progression of the cell cycle. Also, G1 phase-synchronized cells showed a dose-dependent increase of mtDNAcn at 48 h after X-ray exposure, whereas G2 cells showed a dose-dependent increase at 24 h. In addition, S phase-synchronized cells showed a dose-dependent increase at 24 and 48 h after irradiation. These results showed the cell cycle- and dose-dependent effects on mtDNAcn after irradiation, which might shed light on the emerging role of mitochondrial genome and in cell survival.
Related Concept Videos
Mutations
Chromosomal Alterations Are Large-Scale Mutations
While point mutations are changes in a single nucleotide in...
Spontaneous and Induced Mutations
Electron Transport Chain: Complex I and II
ROS generation is regulated and maintained at moderate levels necessary...
Animal Mitochondrial Genetics
Biological Effects of Radiation
Nucleotide Excision Repair
Cells are regularly exposed to mutagens—factors in the environment that can damage DNA and generate mutations. UV radiation is one of the most common mutagens and is estimated to introduce a significant number of changes in DNA. These include bends or kinks in the structure, which can block DNA replication or transcription. If these errors are not fixed, the damage can cause mutations, which in turn can result in cancer or disease depending on which sequences are...

