Project description:According to recent reports, exposure to environmental endocrine disrupting chemicals (EDs) during pregnancy may harm multiple subsequent generations. We hypothesized that EDs must directly alter DNA methylation and/or transcription in the exposed fetal germ cells to affect the grandchild. In addition, the aberrant pattern must be retained in the germ cells of the grandchild -- withstanding global epigenome remodeling -- to affect the great-grandchild. To test this hypothesis, we extensively searched for immediate and persistent epigenetic effects in purified germ cells of the exposed fetus and those of the next generation. We treated gestating female mice with previously validated doses of vinclozolin (VZ), bisphenol A (BPA), di-(2-ethylhexyl) phthalate (DEHP), or control oil, during the time when the prospermatogonia of the exposed fetus undergo global de novo DNA methylation. Using genome-wide assays, we detected changes in transcription and DNA methylation in the exposed prospermatogonia but these did not persist into the prospermatogonia of the next generation. There was no evidence for transgenerational inheritance of these epigenetic aberrations. Our results suggest that EDs exert direct epigenetic effects in the exposed fetal germ cells, but the germline corrects against deleterious effects in the next generation. Pregnant mice were gavaged daily with endocrine distruptors (VZ at 100 mg/kg/day, DEHP at 750 mg/kg/day, BPA at 0.2 mg/kg/day or control oil) starting at 12.5 days post coitum (dpc) and the G1R germ cells were purified from the exposed fetuses at 17.5 dpc. The G2R germ cells were purified from fetuses that were sired by males that had been treated in utero in a G0 mother. G1R spermatozoa were collected from adult males that had been treated in utero at the fetal stages. G2R spermatozoa were collected from adult males who were sired by in-uteo-treated males.
Project description:According to recent reports, exposure to environmental endocrine disrupting chemicals (EDs) during pregnancy may harm multiple subsequent generations. We hypothesized that EDs must directly alter DNA methylation and/or transcription in the exposed fetal germ cells to affect the grandchild. In addition, the aberrant pattern must be retained in the germ cells of the grandchild -- withstanding global epigenome remodeling -- to affect the great-grandchild. To test this hypothesis, we extensively searched for immediate and persistent epigenetic effects in purified germ cells of the exposed fetus and those of the next generation. We treated gestating female mice with previously validated doses of vinclozolin (VZ), bisphenol A (BPA), di-(2-ethylhexyl) phthalate (DEHP), or control oil, during the time when the prospermatogonia of the exposed fetus undergo global de novo DNA methylation. Using genome-wide assays, we detected changes in transcription and DNA methylation in the exposed prospermatogonia but these did not persist into the prospermatogonia of the next generation. There was no evidence for transgenerational inheritance of these epigenetic aberrations. Our results suggest that EDs exert direct epigenetic effects in the exposed fetal germ cells, but the germline corrects against deleterious effects in the next generation. Pregnant mice were gavaged daily with endocrine distruptors (VZ at 100 mg/kg/day, DEHP at 750 mg/kg/day, BPA at 0.2 mg/kg/day or control oil) starting at 12.5 days post coitum (dpc) and the G1R germ cells were purified from the exposed fetuses at 17.5 dpc. The G2R germ cells were purified from fetuses that were sired by males that had been treated in utero in a G0 mother. G1R spermatozoa were collected from adult males that had been treated in utero at the fetal stages. G2R spermatozoa were collected from adult males who were sired by in-uteo-treated males.
Project description:Embryonic exposure to the endocrine disruptor vinclozolin during gonadal sex determination appears to promote an epigenetic reprogramming of the male germ line that is associated with transgenerational adult-onset disease states. Transgenerational effects on the embryonic day 16 (E16) testis demonstrated reproducible changes in the testis transcriptome for multiple generations (F1-F3). The expression of 196 genes was found to be influenced, with the majority of gene expression being decreased or silenced. Dramatic changes in the gene expression of methyltransferases during gonadal sex determination were observed in the F1 and F2 vinclozolin generation (E16) embryonic testis, but the majority returned to control-generation levels by the F3 generation. The most dramatic effects were on the germ-line-associated Dnmt3A and Dnmt3L isoforms. Observations demonstrate that an embryonic exposure to vinclozolin appears to promote an epigenetic reprogramming of the male germ line that correlates with transgenerational alterations in the testis transcriptome in subsequent generations. Experiment Overall Design: E16 Testis RNA samples from F1, F2, F3 generation control groups are compared to F1, F2, F3 generation vinclozolin treated groups