mtDNA polymorphism and metabolic inhibition affect sperm performance in conplastic mice

Area of Science:

• Mitochondrial genetics
• Reproductive biology
• Sperm physiology

Background:

• Mitochondrial DNA (mtDNA) substitutions link to metabolic diseases.
• mtDNA's maternal inheritance suggests relevance for male reproductive traits.
• The role of mitochondrial function in sperm ATP production and motility is unclear.

Purpose of the Study:

• To investigate the impact of specific mitochondrial DNA (mtDNA) genotypes on mouse sperm performance and bioenergetics.
• To determine if mtDNA polymorphisms affect sperm motility and ATP production.
• To explore the relationship between the extent of mtDNA variation and sperm function.

Main Methods:

• Utilized five conplastic inbred mouse strains with identical nuclear backgrounds but different mtDNA genomes.
• Assessed sperm progressive velocity and bioenergetic parameters.
• Examined sperm performance response to inhibitors of key metabolic pathways.

Main Results:

• mtDNA polymorphisms across different haplotypes correlated with altered sperm progressive velocity.
• No association was found between mtDNA variations and sperm ATP production.
• The degree of mtDNA polymorphism did not correlate with the magnitude of sperm performance decrease or its response to metabolic inhibition.

Conclusions:

• Variability in mouse sperm performance is linked to mtDNA genetic polymorphisms, independent of ATP production.
• Observed differences may result from additive effects of single nucleotide substitutions or disrupted co-evolved nuclear-mtDNA interactions.
• Further research is needed to elucidate the precise mechanisms linking mtDNA genotype to male reproductive traits.