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Updated: Jun 28, 2025
07:11
Laser Micro-Irradiation to Study DNA Recruitment During S Phase
Published on: April 16, 2021
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DNA repair is efficient in irradiated M phase zygotes
Yuan Wang1,2, Dai Tsukioka2, Shoji Oda2
1Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8562, Japan.
The Journal of Reproduction and Development
|April 21, 2024
Summary
DNA repair is active in M phase mouse zygotes, causing anaphase bridges after irradiation. Removing H2AX improves embryo development, suggesting zygote DNA repair is critical for preventing mutation transmission.
Area of Science:
- Developmental Biology
- Molecular Biology
- Genetics
Background:
- DNA repair is typically suppressed during mitosis in somatic cells to ensure accurate chromosome segregation.
- Irradiation-induced DNA damage markers like γH2AX foci usually persist in mitotic somatic cells.
Purpose of the Study:
- To investigate DNA repair dynamics and consequences in M phase mouse zygotes following irradiation.
- To determine the role of H2AX in chromosome segregation and early embryonic development after DNA damage.
Main Methods:
- Irradiation of mouse zygotes during M phase.
- Immunofluorescence microscopy to detect γH2AX foci and monitor chromosome segregation.
- Analysis of embryo development to the blastocyst stage in wild-type and H2AX-deficient zygotes.
Main Results:
- Anaphase bridges frequently formed in irradiated M phase zygotes.
- γH2AX signals peaked at 30 min post-irradiation and had a half-life of 1-2 hours in zygotes, indicating efficient repair.
- Absence of H2AX facilitated sister chromatid segregation and improved blastocyst development.
Conclusions:
- The DNA repair system is highly active in M phase zygotes, leading to frequent anaphase bridges upon irradiation.
- Differential regulation of DNA repair in M phase zygotes may serve to eliminate damaged embryos, preventing mutation transmission to offspring.
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