Comparative Sperm Proteomics in Mouse Species with Divergent Mating Systems.

Area of Science:

• Evolutionary Biology
• Reproductive Biology
• Proteomics

Background:

• Sexual selection significantly shapes sperm form and function.
• Testis gene expression evolves rapidly, but the proteomic basis of sperm diversity is underexplored.

Purpose of the Study:

• To characterize sperm proteomic divergence in closely related Mus species.
• To investigate the link between sperm competition regimes and sperm protein composition, energetics, motility, and fertilization capacity.

Main Methods:

• Whole-cell proteomics approach applied to sperm from different Mus species.
• Interspecific comparisons of protein abundance.
• Ancestral reconstruction of relative testis size.
• Comparison of protein abundance with stage-specific testis expression.

Main Results:

• Significant abundance differences in proteins related to fertilization capacity, sperm energetics, and motility were found.
• Reduced sperm competition in M. musculus correlated with decreased zona pellucida binding proteins and heavy-chain dyneins.
• High sperm competition species showed decreased glycolytic proteins, indicating reduced reliance on glycolysis for ATP.
• Proteins involved in sperm diversification were more prone to translational repression.

Conclusions:

• Sperm proteomic composition is significantly impacted by both intensified and relaxed sperm competition.
• Evolutionary proteomic analyses are valuable for understanding sperm diversification.
• Translational control mechanisms may play a role in shaping sperm composition.