Related Experiment Video
Updated: Jul 11, 2026
Measuring Single-Cell Mitochondrial DNA Copy Number and Heteroplasmy Using Digital Droplet Polymerase Chain Reaction
Published on: July 12, 2022
Mitochondrial DNA deletions in rhesus macaque oocytes and embryos
T C Gibson1, H M Kubisch, C A Brenner
1Department of Biological Sciences, University of New Orleans, New Orleans, LA 70122, USA.
Abstract:
Mitochondria are the most abundant organelles in mammalian oocytes and early embryos. Mitochondrial DNA (mtDNA) mutations, including the common deletion, have been found in skeletal muscle fibres from aged rhesus macaques. The specific aims of this study were to determine whether the mitochondrial common deletion is present in rhesus oocytes after hormonal stimulation and in embryos generated by in vitro production, or whether this deletion is already present in the immature oocyte. Using a nested primer PCR strategy, we found a significant increase in the proportion of mtDNA deletions in stimulated oocytes and embryos from rhesus macaques, compared with mtDNA deletions in immature, unstimulated oocytes derived from necropsied ovaries of age-matched monkeys. The common deletion is larger in the rhesus (5704 bp) than in humans (4977 bp). Accumulation of mtDNA deletions in oocytes may contribute to mitochondrial dysfunction and impaired ATP production. We propose the rhesus to be an excellent model to assess the quality of gametes and embryos and their developmental competence in primates, including humans.
Insights
Mitochondrial DNA deletions increase in rhesus monkey oocytes and embryos after stimulation. This suggests accumulation of these mutations may impact reproductive quality in primates.
Area of Science:
- Reproductive Biology
- Mitochondrial Genetics
- Primate Development
Background:
- Mitochondria are vital organelles in oocytes and early embryos.
- Mitochondrial DNA (mtDNA) deletions are linked to aging and cellular dysfunction.
- The common mtDNA deletion's presence in primate oocytes and embryos is not well understood.
Purpose of the Study:
- To investigate the presence and changes in the mitochondrial common deletion in rhesus macaque oocytes and embryos.
- To compare deletion levels in immature oocytes versus stimulated oocytes and in vitro produced embryos.
- To establish the rhesus macaque as a model for primate gamete and embryo quality assessment.
Main Methods:
- Nested primer PCR strategy to detect mitochondrial DNA deletions.
- Analysis of immature oocytes, hormonally stimulated oocytes, and in vitro produced embryos.
- Comparison of mtDNA deletion proportions across different sample types and conditions.
Main Results:
- A significant increase in the proportion of mtDNA deletions was observed in stimulated oocytes and embryos compared to immature oocytes.
- The common deletion in rhesus macaques is larger (5704 bp) than in humans (4977 bp).
- Results indicate mtDNA deletions accumulate during oocyte maturation and early embryonic development.
Conclusions:
- Mitochondrial DNA deletions accumulate in rhesus oocytes and embryos, potentially affecting mitochondrial function and ATP production.
- Hormonal stimulation and in vitro production may influence the accumulation of mtDNA deletions.
- The rhesus macaque serves as a valuable model for studying gamete and embryo quality and developmental competence in primates.
