Decreased fecundity and sperm DNA methylation patterns

Area of Science:

• Reproductive Biology
• Epigenetics
• Genomics

Background:

• Male fecundity is crucial for natural conception.
• Epigenetic modifications, such as DNA methylation, play a role in gene regulation and can be influenced by environmental factors.
• Sperm epigenetics is an emerging area of research for understanding male infertility.

Purpose of the Study:

• To investigate the association between sperm DNA methylation patterns and male fecundity.
• To identify specific genomic regions or genes in sperm that exhibit differential methylation in men with varying fertility levels.

Main Methods:

• Prospective study design.
• Analysis of DNA methylation using the human methylation 450k array on sperm samples.
• Comparison of methylation patterns between men from couples who conceived quickly and those with delayed conception.
• Standard semen analysis including sperm count, morphology, and volume.

Main Results:

• No significant differences in standard semen parameters were found between fertile and subfertile groups.
• Identified five genomic regions with statistically significant differential DNA methylation in sperm.
• Two regions with decreased methylation and three with increased methylation were associated with the failure-to-conceive group.
• Decreased methylation at HSPA1L and HSPA1B genes correlated with reduced fecundity.

Conclusions:

• Alterations in sperm DNA methylation are associated with decreased male fecundity.
• Specific genomic loci, including HSPA1L and HSPA1B, are identified as potential candidates for further research.
• These findings suggest a role for epigenetic modifications in sperm in determining fertility outcomes.