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Updated: Mar 21, 2026
Multi-Photon Laser Ablation of Cytoplasmic Microtubule Organizing Centers in Mouse Oocytes
Published on: November 11, 2022
Eccentric localization of catalase to protect chromosomes from oxidative damages during meiotic maturation in mouse
Yong Seok Park1, Seung Yeop You1, Sungrae Cho1
1Department of Genetic Engineering, College of Biotechnology and Bioengineering, Sungkyunkwan University, Suwon, Gyeonggi-do, 440-746, Korea.
Abstract:
The maintenance of genomic integrity and stability is essential for the survival of every organism. Unfortunately, DNA is vulnerable to attack by a variety of damaging agents. Oxidative stress is a major cause of DNA damage because reactive oxygen species (ROS) are produced as by-products of normal cellular metabolism. Cells have developed eloquent antioxidant defense systems to protect themselves from oxidative damage along with aerobic metabolism. Here, we show that catalase (CAT) is present in mouse oocytes to protect the genome from oxidative damage during meiotic maturation. CAT was expressed in the nucleus to form unique vesicular structures. However, after nuclear envelope breakdown, CAT was redistributed in the cytoplasm with particular focus at the chromosomes. Inhibition of CAT activity increased endogenous ROS levels, but did not perturb meiotic maturation. In addition, CAT inhibition produced chromosomal defects, including chromosome misalignment and DNA damage. Therefore, our data suggest that CAT is required not only to scavenge ROS, but also to protect DNA from oxidative damage during meiotic maturation in mouse oocytes.
Insights
Catalase (CAT) protects mouse oocytes from DNA damage caused by oxidative stress during meiosis. Inhibition of CAT increases reactive oxygen species (ROS) and leads to chromosomal defects, highlighting its crucial role in maintaining genomic stability.
Area of Science:
- Cell Biology
- Genetics
- Reproductive Biology
Background:
- Genomic integrity is vital for organism survival.
- Oxidative stress from reactive oxygen species (ROS) is a significant source of DNA damage.
- Cells possess antioxidant systems to counteract oxidative damage.
Purpose of the Study:
- To investigate the role of catalase (CAT) in protecting mouse oocytes from oxidative DNA damage during meiotic maturation.
- To determine the localization and function of CAT in oocytes.
Main Methods:
- Immunofluorescence microscopy to observe CAT localization in mouse oocytes.
- Inhibition of CAT activity using specific inhibitors.
- Assessment of reactive oxygen species (ROS) levels.
- Analysis of meiotic maturation progression and chromosomal integrity.
Main Results:
- Catalase (CAT) is present in mouse oocytes, initially in the nucleus and later redistributed to chromosomes after nuclear envelope breakdown.
- Inhibition of CAT activity elevated endogenous ROS levels.
- CAT inhibition resulted in chromosomal defects, including misalignment and DNA damage, without affecting meiotic maturation progression.
Conclusions:
- Catalase (CAT) plays a critical role in scavenging ROS and protecting DNA from oxidative damage during mouse oocyte meiotic maturation.
- CAT is essential for maintaining chromosomal integrity in oocytes.
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