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Updated: Feb 23, 2026
Fluorimetric Techniques for the Assessment of Sperm Membranes
Published on: November 28, 2018
Effect of sodium fluoride on the sperm mitochondrial DNA in mice
Zilong Sun1, Xingchen Xue2, Yuliang Zhang2
1College of Animal Science and Veterinary Medicine, Shanxi Agricultural University, Taigu, Shanxi 030801, PR China; Shanxi Key Laboratory of Ecological Animal Science and Environmental Veterinary Medicine, Shanxi Agricultural University, Taigu, Shanxi 030801, PR China.
Abstract:
Previous studies demonstrated that fluoride, as a widespread environmental pollutant, induced the reproductive toxicity at high dose. Besides the decrease of sperm characteristics like concentration, survival, and sperm motility, it was found that high fluoride induced the destructive mitochondrial ultrastructure and decreased ATP production from mitochondrial respiration. However, whether fluoride exposure can damage the mitochondrial DNA (mtDNA) of sperm is still unknown. In this study, 100 male mice were randomly divided into four groups 25 each, which were administrated with the distilled water containing 0, 25, 50 and 100 mg L-1 NaF, respectively for 60 days. After exposure, sperm mtDNA copy number was measured by real-time PCR, mtDNA integrity by acridine orange (AO) staining, and nuclear DNA (nDNA) integrity through long PCR amplification, as well as MTCYB and MTATP6 mutations by PCR and direct sequencing. The results showed that 100 mg L-1 NaF significantly increased sperm mtDNA copy number, and reduced nDNA integrity. There were no changes observed in mtDNA integrity, and mutations of MTCYB and MTATP6 between fluoride groups and the control group. These results indicated that along with low sperm quality, sperm mtDNA copy number is also a sensitive biomarker to reflect the sperm toxicity of fluoride.
Insights
High fluoride exposure in male mice increased sperm mitochondrial DNA (mtDNA) copy number and reduced nuclear DNA (nDNA) integrity, indicating potential reproductive toxicity. Sperm mtDNA copy number serves as a sensitive biomarker for fluoride-induced sperm damage.
Area of Science:
- Environmental Toxicology
- Reproductive Biology
- Mitochondrial DNA Research
Background:
- Fluoride is a common environmental pollutant known to cause reproductive toxicity at high doses.
- Previous research linked high fluoride exposure to decreased sperm quality, mitochondrial damage, and reduced ATP production.
- The impact of fluoride on sperm mitochondrial DNA (mtDNA) integrity and copy number remained largely uninvestigated.
Purpose of the Study:
- To investigate the effects of chronic fluoride exposure on sperm mitochondrial DNA (mtDNA) and nuclear DNA (nDNA) integrity in male mice.
- To determine if fluoride exposure alters sperm mtDNA copy number and specific gene mutations (MTCYB, MTATP6).
Main Methods:
- Male mice were exposed to varying concentrations of sodium fluoride (NaF) (0, 25, 50, 100 mg/L) for 60 days.
- Sperm mtDNA copy number was quantified using real-time PCR.
- mtDNA integrity was assessed via acridine orange (AO) staining, nDNA integrity through long PCR amplification, and gene mutations via PCR and sequencing.
Main Results:
- Exposure to 100 mg/L NaF significantly increased sperm mtDNA copy number compared to controls.
- High fluoride exposure led to a significant reduction in sperm nuclear DNA (nDNA) integrity.
- No significant changes were observed in mtDNA integrity or MTCYB/MTATP6 gene mutations across fluoride exposure groups.
Conclusions:
- Sperm mitochondrial DNA (mtDNA) copy number is a sensitive biomarker for detecting fluoride-induced reproductive toxicity.
- Fluoride exposure negatively impacts sperm quality, evidenced by altered mtDNA copy number and reduced nDNA integrity.
- Further research is warranted to elucidate the mechanisms underlying fluoride's effects on sperm DNA.
