Project description:Atrazine is a common agricultural herbicide previously shown to promote epigenetic transgenerational inheritance of disease to subsequent generations. The current study was designed as an epigenome-wide association study (EWAS) to identify transgenerational sperm disease associated differential histone retention regions (DHRs). Gestating female F0 generation rats were transiently exposed to atrazine during the period of embryonic gonadal sex determination, and then subsequent F1, F2, and F3 generations obtained in the absence of any continued exposure. The transgenerational F3 generation males were assessed for disease and sperm collected for epigenetic analysis. Pathology was observed in late pubertal onset and for testis disease, prostate disease, kidney disease, lean pathology, and multiple disease. For these pathologies, sufficient numbers of individual males with only a single specific disease were identified. The sperm DNA and chromatin were isolated from adult one-year animals with the specific diseases and analyzed for DHRs with histone chromatin immunoprecipitation (ChIP) sequencing. Transgenerational F3 generation males with or without disease were compared to identify the disease specific epimutation biomarkers. No common DHRs were found among all the pathologies. Epimutation gene associations were identified and found to correlate to previously known disease linked genes.
Project description:Environmental compounds including fungicides, plastics, pesticides, dioxin and hydrocarbons can promote the epigenetic transgenerational inheritance of adult-onset disease in future generation progeny following ancestral exposure during the critical period of fetal gonadal sex determination. This study examined the actions of the pesticide methoxychlor to promote the epigenetic transgenerational inheritance of adult-onset disease and associated differential DNA methylation regions (i.e. epimutations) in sperm. Gestating F0 generation female rats were transiently exposed to methoxychlor during fetal gonadal development (gestation days 8 to 14) and then adult-onset disease was evaluated in adult F1 and F3 (great-grand offspring) generation progeny for control (vehicle exposed) and methoxychlor lineage offspring. There were increases in the incidence of kidney disease, ovary disease, and obesity in the methoxychlor lineage animals. In females and males the incidence of disease increased in both the F1 and the F3 generations and the incidence of multiple disease increased in the F3 generation. There was increased disease incidence in F4 generation reverse outcross (female) offspring indicating disease transmission was primarily transmitted through the female germline. Analysis of the F3 generation sperm epigenome of the methoxychlor lineage males identified differentially DNA methylated regions (DMR) termed epimutations in a genome-wide gene promoters analysis. These epimutations were found to be methoxychlor exposure specific in comparison with other exposure specific sperm epimutation signatures. Observations indicate that the pesticide methoxychlor has the potential to promote the epigenetic transgenerational inheritance of disease and the sperm epimutations appear to provide exposure specific epigenetic biomarkers for transgenerational disease and ancestral environmental exposures. Methylated sperm DNA was isolated from rats ancestrally exposed to methoxychlor. Three independent samples from each treatment group were obtained. Differential DNA methylation between treatment groups was determined using Nimblegen microarrays. Treated samples were paired with control samples and hybridized together on arrays, resulting in three arrays for the treatment.
Project description:Several epigenome-wide association studies (EWAS) have been shown to identify epigenetic alterations (i.e., epimutations) associated with diseases. The sperm epimutations potentially involved in the transgenerational inheritance of specific pathologies have been identified. Transgenerational sperm epimutations associated with kidney, prostate, puberty, testis, obesity, and multiple pathologies have been identified for a variety of environmental toxicants including dioxin, plastics, pesticides, glyphosate, methoxychlor, atrazine, and jet fuel. The transgenerational sperm epimutations for exposure and disease-specific epimutations have been identified in these EWAS studies. The current study used the information from these previous toxicant-induced epigenetic transgenerational inheritance EWAS rat studies and adds a comparable control group, rats that have not been exposed to any particular toxicant. Two additional control groups were collected and are presented here.
Project description:Plastic derived compounds are one of the most frequent daily world-wide exposures. Previously a mixture of plastic derived toxicants involving bisphenol A (BPA), Bis(2-ethylhexyl) phthalate (DEHP), and dibutyl phthalate (DBP) at lower dose exposures of a gestating female rat were found to promote the epigenetic transgenerational inheritance of disease to the offspring (F1 generation), grand-offspring (F2 generation) and great-grand-offspring (F3 generation). Epigenetic analysis of the male sperm was found to result in differential DNA methylation regions (DMRs) in the transgenerational F3 generation male sperm. The current study is distinct and was designed to identify potential sperm DNA methylation biomarkers for specific transgenerational diseases. Observations show disease specific DMRs called epimutations in the transgenerational F3 generation great-grand-offspring rats ancestrally exposed to plastics. The epigenetic DMR biomarkers were identified for testis disease, kidney disease, and multiple (≥2) diseases. These disease sperm epimutation biomarkers were found to be predominantly disease specific. The genomic locations and features of these DMRs were identified. Interestingly, the disease specific DMR associated genes were previously shown to be linked with each of the specific diseases. Therefore, the germline has ancestrally derived epimutations that potentially transmit transgenerational disease susceptibilities. Epigenetic biomarkers for specific diseases could be used as diagnostics to facilitate clinical management of disease and preventative medicine.
Project description:This study examined the potential transgenerational actions of the herbicide atrazine. The F1 generation offspring (directly exposed as a fetus) derived from the F0 generation exposed gestating female rats did not develop disease, but weighed less compared to controls. The F2 generation (grand-offspring) was found to have increased frequency of testis disease, increased frequency of tumor development in males and females (predominately mammary tumors), early onset puberty in males, and decreased body weight in females compared to controls. The transgenerational F3 generation rats were found to have increased frequency of testis disease, early onset puberty in females, behavioral alterations and a lean phenotype in males and females involving a reduced adipocyte size, decreased body mass index (BMI) and reduced adiposity. The frequency of multiple diseases was significantly higher in the transgenerational F3 generation atrazine lineage males and females. The sperm differential DNA methylation regions (DMRs), termed epimutations, induced by atrazine were identified. A comparison of control versus atrazine lineage sperm identified 519 DMRs (p<10-6) for the F1 generation, 431 DMR (p<10-5) for the F2 generation, and 958 DMR (p<10-9) for the transgenerational F3 generation sperm.
Project description:Environmental compounds including fungicides, plastics, pesticides, dioxin and hydrocarbons can promote the epigenetic transgenerational inheritance of adult-onset disease in future generation progeny following ancestral exposure during the critical period of fetal gonadal sex determination. This study examined the actions of the pesticide methoxychlor to promote the epigenetic transgenerational inheritance of adult-onset disease and associated differential DNA methylation regions (i.e. epimutations) in sperm. Gestating F0 generation female rats were transiently exposed to methoxychlor during fetal gonadal development (gestation days 8 to 14) and then adult-onset disease was evaluated in adult F1 and F3 (great-grand offspring) generation progeny for control (vehicle exposed) and methoxychlor lineage offspring. There were increases in the incidence of kidney disease, ovary disease, and obesity in the methoxychlor lineage animals. In females and males the incidence of disease increased in both the F1 and the F3 generations and the incidence of multiple disease increased in the F3 generation. There was increased disease incidence in F4 generation reverse outcross (female) offspring indicating disease transmission was primarily transmitted through the female germline. Analysis of the F3 generation sperm epigenome of the methoxychlor lineage males identified differentially DNA methylated regions (DMR) termed epimutations in a genome-wide gene promoters analysis. These epimutations were found to be methoxychlor exposure specific in comparison with other exposure specific sperm epimutation signatures. Observations indicate that the pesticide methoxychlor has the potential to promote the epigenetic transgenerational inheritance of disease and the sperm epimutations appear to provide exposure specific epigenetic biomarkers for transgenerational disease and ancestral environmental exposures.
Project description:Dioxin is one of the most common historic industrial contaminants with several major industry and government accidents having exposed large numbers of the worldwide population over the past century. Previous rat studies have demonstrated the ability of dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)) exposure to promote the epigenetic transgenerational inheritance of disease susceptibility in subsequent generations. The types of disease observed include testis, ovary, kidney, prostate and obesity pathologies. The current study was designed to use an epigenome-wide association study (EWAS) to identify potential sperm DNA methylation biomarkers for specific transgenerational diseases. The transgenerational F3 generation dioxin lineage male rats with and without a specific disease were compared to identify differential DNA methylation regions (DMRs). The genomic features of the DMRs are characterized. Observations demonstrate that disease specific epimutation DMRs exist for the transgenerational dioxin lineage rats that can potentially be used as epigenetic biomarkers for testis, ovary, kidney, prostate and obesity diseases. These disease specific DMRs were associated with genes that have previously been shown to be linked with these diseases. This EWAS for transgenerational disease identified epigenetic biomarkers and provides the proof of concept of the potential to develop similar biomarkers for humans to diagnose disease susceptibilities and facilitate preventative medicine.
Project description:The herbicide glyphosate has been shown to promote the epigenetic transgenerational inheritance of pathology and disease in subsequent great-grand offspring (F3 generation). This generational toxicology suggests the impacts of environmental exposures need to assess subsequent generations. The current study was designed to identify epigenetic biomarkers for glyphosate induced transgenerational disease. Following a transient glyphosate exposure of a gestating female rat (F0 generation), the subsequent transgenerational F3 generation, with no direct exposure, were aged to 1 year and animals with specific pathologies identified. The pathologies investigated included prostate disease, kidney disease, obesity, and presence of multiple disease. The sperm were collected from the males and used to identify specific differential DNA methylation regions (DMRs) associated with the pathologies. In addition, the differential histone retention sites (DHRs) were examined for the various pathologies as well. Unique signatures of DMRs and DHRs for each pathology were identified for the specific diseases. Interestingly, at a lower statistical threshold overlapping sets of DMRs and DHRs were identified that were common for all the pathologies. The DMR and DHR gene associations were identified and correlated with known pathology associated genes. While the disease biomarker DMR and DHR did not meet typical statistical significance levels, these results may help design future studies with reduced variability. Observations indicate transgenerational epigenetic biomarkers of disease pathology can potentially be identified in the sperm that can assess disease susceptibility. These biomarkers may also suggest epigenetic diagnostics could be used to facilitate preventative medicine.