Objective: To assess reliability of a high-throughput assay of sperm DNA methylation.
Design: Observational study comparing DNA methylation of sperm isolated from 3 divided and 12 longitudinally collected semen samples.
Setting: Academic medical center.
Patient(s): One man undergoing screening semen analysis during evaluation of an infertile couple and 2 healthy fertile male volunteers.
Intervention(s): Spermatozoa were separated from seminal plasma and somatic cells using gradient separation. DNA was extracted from spermatozoa, and DNA methylation was assessed at 1,505 DNA sequence-specific sites.
Main outcome measure(s): Repeatability of sperm DNA methylation measures, estimated by correlation coefficients.
Result(s): DNA methylation levels were highly correlated within matched sets of divided samples (all r ≥ 0.97) and longitudinal samples (average r = 0.97).
Conclusion(s): The described methodology reliably assessed methylation of sperm DNA at large numbers of sites. Methylation profiles were consistent over time. High-throughput assessment of sperm DNA methylation is a promising tool for studying the role of epigenetic state in male fertility.
Copyright © 2011 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.