The Effects of Sodium Selenite on Mitochondrial DNA Copy Number and Reactive Oxygen Species Levels of In Vitro Matured Mouse Oocytes

Ghorbanmehr, Nassim; Salehnia, Mojdeh; Amooshahi, Mahboobeh

doi:10.22074/cellj.2018.5430

The Effects of Sodium Selenite on Mitochondrial DNA Copy Number and Reactive Oxygen Species Levels of In Vitro Matured Mouse Oocytes

Document Type : Original Article

Authors

¹ Department of Anatomy, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran;Department of Biotechnology, Faculty of Biological Sciences, Alzahra University, Tehran, Iran

² Department of Anatomy, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran

10.22074/cellj.2018.5430

Abstract

Objective
The aim of present study is to determine the effects of supplementation of oocyte maturation medium with sodium selenite (SS) on oocyte mitochondrial DNA (mtDNA) copy number and reactive oxygen species (ROS) levels.
Materials and Methods
In this experimental study germinal vesicle (GV), metaphase I (MI), and metaphase II (MII) stage oocytes were recovered from 6-8 week old female mice after superovulation. Some of the GV oocytes were cultured and matured in the presence and absence of SS. Then in vivo and in vitro matured (IVM) oocytes were subjected to mitochondria staining by MitoTracker green, ROS analysis, and mtDNA copy number determination using absolute real-time polymerase chain reaction (PCR).
Results
The maturation rate of GV oocytes to the MII stage significantly increased in the SS supplemented group (79.25%) compared to the control group (72.46%, P < 0.05). The intensity of mitochondrial staining was not different among the studied groups, whereas the mitochondria distribution in the cytoplasm of the IVM oocytes showed some aggregation pattern. The in vivo obtained MII oocytes had lower ROS levels and higher mtDNA copy numbers than IVM-MII oocytes (P < 0.05). The SS supplemented group had significantly lower ROS levels and higher mtDNA copy numbers than the non-treated group (P < 0.05).
Conclusion
SS increased oocyte mtDNA copy number by decreasing oxidative stress. SS had an association with better oocyte developmental competence.

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