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Updated: Jun 17, 2026
Use of Bisection to Reduce Mitochondrial DNA in the Bovine Oocyte
Published on: July 6, 2022
Microinjection of serum-starved mitochondria derived from somatic cells affects parthenogenetic development of bovine
Kumiko Takeda1, Mariko Tasai, Satoshi Akagi
1National Institute of Livestock and Grassland Science, National Agriculture and Food Research Organization, Tsukuba 305-0901, Japan. kumiko@affrc.go.jp <kumiko@affrc.go.jp>
Abstract:
Microinjection of isolated mitochondria into oocytes is an effective method to introduce exogenous mitochondrial DNA. In nuclear transfer procedures in which donor cell mitochondria are transferred with nuclei into recipient oocytes; development and survival rates of reconstructed embryos may be also directly influenced by mitochondrial viability. Mitochondrial viability is dramatically affected by cell culture conditions, such as serum starvation prior to nuclear transfer. This study was conducted to examine the influence of exogenous mitochondria using bovine and mouse parthenogenetic models. Mitochondria were isolated from primary cells at confluency and after serum starvation. The bovine oocytes injected with serum-starved mitochondria showed lower rates of morula and blastocyst formation when compared to uninjected controls (P<0.05). However, the developmental rates between non-starved mitochondria injection and controls were not different (P>0.05). The murine oocytes injected with serum-starved mitochondria showed lower rates of development when compared with non-starved mitochondria and controls (P<0.01). In contrast to mitochondria transfer, ooplasm transfer did not affect murine or bovine parthenogenetic development (P>0.05). The overall results showed that injection of serum-starved mitochondria influenced parthenogenetic development of both bovine and murine oocytes. Our results illustrate that the somatic mitochondria introduction accompanying nuclei has the capacity to affect reconstructed embryo development; particularly when using serum-starved cells as donor cells.
Insights
Serum starvation negatively impacts mitochondrial viability, reducing embryo development rates after microinjection into oocytes. This highlights the importance of donor cell conditions in mitochondrial transfer for reproductive technologies.
Area of Science:
- Reproductive Biology
- Cell Biology
- Mitochondrial Biology
Background:
- Mitochondrial viability is crucial for successful embryo development following nuclear transfer.
- Cell culture conditions, such as serum starvation, can significantly impair mitochondrial function.
- Exogenous mitochondria introduced into oocytes can influence developmental outcomes.
Purpose of the Study:
- To investigate the impact of serum-starved mitochondria on parthenogenetic development in bovine and mouse oocytes.
- To compare the effects of injecting serum-starved versus non-starved mitochondria.
- To assess the influence of mitochondrial viability on reconstructed embryo development.
Main Methods:
- Mitochondria were isolated from primary cells cultured to confluency and after serum starvation.
- Isolated mitochondria were microinjected into bovine and mouse oocytes.
- Developmental rates (morula and blastocyst formation) were compared between experimental groups and controls.
- Ooplasm transfer was used as a control for non-mitochondrial cytoplasmic factors.
Main Results:
- Injection of serum-starved mitochondria significantly reduced morula and blastocyst formation rates in bovine oocytes compared to controls (P<0.05).
- Murine oocytes injected with serum-starved mitochondria showed significantly lower developmental rates than those injected with non-starved mitochondria or controls (P<0.01).
- Ooplasm transfer did not affect parthenogenetic development in either species (P>0.05).
Conclusions:
- The viability of donor cell mitochondria, particularly after serum starvation, critically affects parthenogenetic embryo development in both bovine and murine oocytes.
- Somatic mitochondria introduction, especially from compromised cells, can negatively impact reconstructed embryo development.
- Careful consideration of donor cell conditions is essential when utilizing mitochondrial transfer in assisted reproductive technologies.
