Concurrent Measurement of Mitochondrial DNA Copy Number and ATP Concentration in Single Bovine Oocytes

To sustain energy-demanding developmental processes, oocytes must accumulate adequate stores of metabolic substrates and mitochondrial numbers prior to the initiation of maturation. In the past, researchers have utilized pooled samples to study oocyte metabolism, and studies that related multiple metabolic outcomes in single oocytes, such as ATP concentration and mitochondrial DNA copy number, were not possible. Such scenarios decreased sensitivity to intraoocyte metabolic relationships and made it difficult to obtain adequate sample numbers during studies with limited oocyte availability. Therefore, we developed and validated procedures to measure both mitochondrial DNA (mtDNA) copy number and ATP quantity in single oocytes. Validation of our procedures revealed that we could successfully divide oocyte lysates into quarters and measure consistent results from each of the aliquots for both ATP and mtDNA copy number. Coefficient of variation between the values retrieved for mtDNA copy number and ATP quantity quadruplicates were 4.72 ± 0.98 and 1.61 ± 1.19, respectively. We then utilized our methodology to concurrently measure mtDNA copy number and ATP quantity in germinal vesicle (GV) and metaphase two (MII) stage oocytes. Our methods revealed a significant increase in ATP levels (GV = 628.02 ± 199.53 pg, MII = 1326.24 ± 199.86 pg, p < 0.001) and mtDNA copy number (GV = 490,799.4 ± 544,745.9 copies, MII = 1,087,126.9 ± 902,202.8 copies, p = 0.035) in MII compared to GV stage oocytes. This finding is consistent with published literature and provides further validation of the accuracy of our methods. The ability to produce consistent readings and expected results from aliquots of the lysate from a single oocyte reveals the sensitivity and feasibility of using this method.

Download Full-text

Social integration predicts mitochondrial DNA copy number in rhesus macaques

10.1101/408849 ◽

2018 ◽

Author(s):

Reena Debray ◽

Noah Snyder-Mackler ◽

Jordan Kohn ◽

Mark Wilson ◽

Luis Barreiro ◽

...

Keyword(s):

Mitochondrial Dna ◽

Social Stress ◽

Copy Number ◽

Rhesus Macaques ◽

Dominance Rank ◽

Low Rank ◽

Mtdna Copy Number ◽

Dna Copy Number ◽

Chronic Social Stress ◽

Mitochondrial Dna Copy Number

AbstractIn many social mammals, social adversity predicts compromised health and reduced fitness. These effects are thought to be driven in part by chronic social stress, but their molecular underpinnings are not well understood. Recent work suggests that chronic stress can affect mitochondrial copy number, heteroplasmy rates, and function. Here, we tested the first two possibilities, for the first time in nonhuman primates. We manipulated dominance rank in captive female rhesus macaques (n=45), where low rank induces chronic social stress, and measured mitochondrial DNA copy number and heteroplasmy in five peripheral blood mononuclear cell types from each study subject. We found no effect of dominance rank on either mtDNA copy number or heteroplasmy rates. However, grooming rates, a measure of affiliative social behavior predicted by high social status, was positively associated with mtDNA copy number in B cells, cytotoxic T cells, and monocytes. Our results suggest that social interactions can influence mtDNA regulation in immune cells. Further, they indicate the importance of considering both affiliative and competitive interactions in investigating this relationship.

Download Full-text

Effect of maternal age on mitochondrial DNA copy number, ATP content and IVF outcome of bovine oocytes

Reproduction Fertility and Development ◽

10.1071/rd10133 ◽

2011 ◽

Vol 23 (3) ◽

pp. 424 ◽

Cited By ~ 90

Author(s):

Hisataka Iwata ◽

Hiroya Goto ◽

Hiroshi Tanaka ◽

Yosuke Sakaguchi ◽

Koji Kimura ◽

...

Keyword(s):

Mitochondrial Dna ◽

Copy Number ◽

Maternal Age ◽

Ivf Outcome ◽

Atp Content ◽

Dna Copy Number ◽

Mitochondrial Dna Copy Number ◽

Fertilisation Rate ◽

Polymerase Chain ◽

Bovine Oocytes

The primary aim of the present study was to examine the effect of maternal age (in months) on mitochondrial DNA copy number (Mt number), ATP content and IVF outcome of bovine oocytes. We also compared the Mt number of oocytes with fertilisation outcome and ATP content. Oocytes were collected from cows aged 20–204 months and the Mt number was determined by real-time polymerase chain reaction. The Mt number in immature and mature oocytes was determined to be 368 118 and 807 794, respectively; the ATP content in these oocytes was 1.2 and 2.0 pM, respectively. Both Mt number and ATP content increased during oocyte maturation. However, after 90 months of age, the Mt number of mature oocytes decreased with increasing maternal age, whereas the ATP content of mature oocytes was positively correlated with maternal age (P < 0.01); there was no obvious relationship observed between Mt number and ATP content. Furthermore, maternal age was positively correlated with the abnormal fertilisation rate (P < 0.01). Mt number and fertilisation outcome were unrelated, but the nature of this relationship differed between young (21–89 months) and old (>89 months) cows. Thus, we conclude that Mt number, the ATP content and fertilisation outcome of bovine oocytes are affected by maternal age.

Download Full-text