Oral Presentation ESA-SRB-NZSE-CaSR 2026 in conjunction with ENSA

Estrogen's epigenetic legacy: germ cell methylation patterns underlying transgenerational reproductive disease (144624)

Deidre Mattiske 1 , Rachael Rogers 1 , Marci Chai 1 , Tim Hore 2 , Andrew Pask 1
  1. University of Melbourne, Melbourne, VIC, Australia
  2. Department of Anatomy, University of Otago, Dunedin, New Zealand
  1. Background: Prenatal exposure to endocrine disruptors (EDs) is increasingly recognised as a driver of Differences in Sex Development (DSDs) and reproductive dysfunction. Using Diethylstilbestrol (DES)—a synthetic estrogen historically prescribed during pregnancy—as a model ED, we previously demonstrate transgenerational reproductive toxicity across four generations of male mice, characterised by reduced anogenital distance, diminished reproductive organ weights, compromised fertility, and elevated DSD incidence. To determine the mechanism behind these transgenerational impacts, we investigated DNA methylation in male germ cells from F1, F2 and F3 generations of DES exposed mice.
  2. Methods: Pregnant female mice were exposed to DES from days 9-18 of gestation. F1 males were mated with unexposed females to derive F2 and F3 males. Whole genome bisulfite sequencing was performed on male germ cells from F1–F3 generations to identify differentially methylated regions (DMRs) between treatment and control germ cells.
  3. Results: We identified 104 genes with DMRs that were common across F1, F2 and F3 generations and had ≥20% methylation divergence from controls. Strikingly, 43% of these genes are associated with ED-related phenotypes and regulate critical reproductive processes including spermatogenesis, male fertility, and testicular development. In addition, three of these genes have previously been reported as having methylation and gene expression alterations following exposure to DEHP and BPA, indicating conserved mechanisms of action of estrogenic EDs.
  4. Conclusions: Our results provide a comprehensive epigenetic map of transgenerational ED exposure in the male germline and suggest that aberrant DNA methylation in germ cells represents a key mechanism through which estrogens compromise human reproductive health across multiple generations.