Prenatal exposure to benzo[a]pyrene depletes ovarian reserve and masculinizes embryonic ovarian germ cell transcriptome transgenerationally [Bisulfite-Seq]
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ABSTRACT: People are exposed to polycyclic aromatic hydrocarbons, like benzo[a]pyrene (BaP), via inhalation of particulate matter air pollution and ingestion of grilled and smoked foods. Prenatal exposure to BaP destroys germ cells in ovaries, causing earlier onset of ovarian senescence post-natally. Developing testes are affected at higher doses than ovaries. However, it is not known if adverse effects are transmitted to subsequent generations. We orally dosed pregnant female mice (F0) with 0.033, 0.2, or 2 mg/kg-day BaP or vehicle from embryonic day (E) 6.5-11.5 (F1 offspring) or E6.5-15.5 (F2 and F3). Ovarian germ cell and follicle numbers were significantly decreased in F3 females at all doses of BaP; testicular germ cells were not affected. E13.5 germ cell RNA-sequencing revealed significantly increased expression of male-specific genes in female germ cells across generations and BaP doses. Our study demonstrated that F0 BaP exposure partially disrupted sexual identity of female germ cells transgenerationally.
Project description:People are exposed to polycyclic aromatic hydrocarbons, like benzo[a]pyrene (BaP), via inhalation of particulate matter air pollution and ingestion of grilled and smoked foods. Prenatal exposure to BaP destroys germ cells in ovaries, causing earlier onset of ovarian senescence post-natally. Developing testes are affected at higher doses than ovaries. However, it is not known if adverse effects are transmitted to subsequent generations. We orally dosed pregnant female mice (F0) with 0.033, 0.2, or 2 mg/kg-day BaP or vehicle from embryonic day (E) 6.5-11.5 (F1 offspring) or E6.5-15.5 (F2 and F3). Ovarian germ cell and follicle numbers were significantly decreased in F3 females at all doses of BaP; testicular germ cells were not affected. E13.5 germ cell RNA-sequencing revealed significantly increased expression of male-specific genes in female germ cells across generations and BaP doses. Our study demonstrated that F0 BaP exposure partially disrupted sexual identity of female germ cells transgenerationally.
Project description:People are exposed to polycyclic aromatic hydrocarbons, like benzo[a]pyrene (BaP), via inhalation of particulate matter air pollution and ingestion of grilled and smoked foods. Prenatal exposure to BaP destroys germ cells in ovaries, causing earlier onset of ovarian senescence post-natally. Developing testes are affected at higher doses than ovaries. However, it is not known if adverse effects are transmitted to subsequent generations. We orally dosed pregnant female mice (F0) with 0.033, 0.2, or 2 mg/kg-day BaP or vehicle from embryonic day (E) 6.5-11.5 (F1 offspring) or E6.5-15.5 (F2 and F3). Ovarian germ cell and follicle numbers were significantly decreased in F3 females at all doses of BaP; testicular germ cells were not affected. E13.5 germ cell RNA-sequencing revealed significantly increased expression of male-specific genes in female germ cells across generations and BaP doses. Our study demonstrated that F0 BaP exposure partially disrupted sexual identity of female germ cells transgenerationally.
Project description:People are exposed to polycyclic aromatic hydrocarbons, like benzo[a]pyrene (BaP), via inhalation of particulate matter air pollution and ingestion of grilled and smoked foods. Prenatal exposure to BaP destroys germ cells in ovaries, causing earlier onset of ovarian senescence post-natally. Developing testes are affected at higher doses than ovaries. However, it is not known if adverse effects are transmitted to subsequent generations. We orally dosed pregnant female mice (F0) with 0.033, 0.2, or 2 mg/kg-day BaP or vehicle from embryonic day (E) 6.5-11.5 (F1 offspring) or E6.5-15.5 (F2 and F3). Ovarian germ cell and follicle numbers were significantly decreased in F3 females at all doses of BaP; testicular germ cells were not affected. E13.5 germ cell RNA-sequencing revealed significantly increased expression of male-specific genes in female germ cells across generations and BaP doses. Our study demonstrated that F0 BaP exposure partially disrupted sexual identity of female germ cells transgenerationally.
Project description:Stress and glucocorticoid exposure during pregnancy alters neurodevelopment and behavior in offspring, and these effects extend multiple generations through a paternal lineage. The epigenetic mechanisms that govern this transgenerational transmission are unclear. We hypothesized that maternal exposure to multiple courses of sGC in late pregnancy would result in altered miRNA levels in germs cells of male guinea pigs across three generations. Further, our behavioral data indicate that F2 females exhibit altered behaviors following sGC exposure. Thus, we evaluated the miRNA profile of F2 female prefrontal cortex to determine the mechanisms responsible for these behavioral changes and to compare these data to our germ cell miRNA analysis. We used miRNA microarray to evaluate the miRNA levels in F1-F3 germ cells and F2 female PFC in guinea pigs that were exposed to control and F0 prenatal sGC exposure. We identified no significant changes to miRNA levels in both F1-F3 germ cells and F2 PFC from guinea pigs in the sGC group.
Project description:Obesogens such as tributyltin (TBT) are xenobiotic compounds that promote obesity, in part by distorting the normal balance of lipid metabolism. The obesogenic effects of TBT can be observed in directly exposed (F1 and F2 generations) and also subsequent generations (F3 and beyond) that were never exposed. To address the effects of TBT exposure on germ cells, we exposed pregnant transgenic OG2 mouse dams (F0), which specifically express EGFP in germline cells, to an environmentally relevant dose of TBT throughout gestation through drinking water. When fed with a high fat diet (HFD), F3 male offspring of TBT-exposed F0 dams (TBT-F3) accumulated much more body fat than did Control-F3 males. TBT-F3 males also lost more body fluid and lean compositions than did Control-F3 males. Expression of genes involved in transcriptional regulation or mesenchymal differ-entiation was upregulated in somatic cells of TBT-F1 (but not TBT-F3) E18.5 fetal testes, and promoter-associated CpG islands were hyper-methylated in TBT-F1 somatic cells. Global mRNA expression of protein-coding genes in F1 or F3 fetal testicular cells was unaffected by F0 exposure to TBT; however, expression of a subset of endogenous retroviruses was significantly affected in F1 and F3. We infer that TBT may directly target testicular somatic cells in F1 testes to irreversibly affect epigenetic suppression of endogenous retroviruses in both germline and somatic cells.
Project description:In rats, direct exposure to TCDD causes myriad toxicities. Exposed rats experience hepatotoxicity, wasting syndrome and immune suppression, amongst others. “Inherited exposure”, as occurs in the F3 generation of directly exposed F0 animals, has also been shown to cause toxicity: both male and female F3 rats demonstrate an increased incidence of adult onset disease, females also display reproductive abnormalities and increased incidence of ovarian diseases while males show increased incidence of kidney disease and an altered sperm epigenome. Here, we explore the hepatic transcriptomic profile of male and female F3 Sprague-Dawley rats bred through the paternal germ line from F0 dams exposed to a single dose of TCDD (0, 30, 100, 300 or 1000 ng/kg body weight) by oral gavage. We hypothesize that RNA transcripts with altered abundance in livers of unexposed F3 progeny of treated F0 Sprague-Dawley rats may result from epigenetic modifications to the genome. Female F3 rats demonstrated more TCDD-mediated hepatic transcriptomic changes than males, with differences primarily in the lowest dose group.
Project description:Environmental factors during fetal development can induce a permanent epigenetic change in the germ line (sperm) that then transmits epigenetic transgenerational inheritance of adult-onset disease in the absence of any subsequent exposure. The epigenetic transgenerational actions of various environmental compounds and relevant mixtures were investigated with the use of a pesticide mixture (permethrin and insect repellant DEET), a plastic mixture (bisphenol A and phthalates), dioxin (TCDD) and a hydrocarbon mixture (jet fuel, JP8). After transient exposure of F0 gestating female rats during the period of embryonic gonadal sex determination, the subsequent F1-F3 generations were obtained in the absence of any environmental exposure. The effects on the F1, F2 and F3 generations pubertal onset and gonadal function were assessed. The plastics, dioxin and jet fuel were found to promote early-onset female puberty transgenerationally (F3 generation). Spermatogenic cell apoptosis was affected transgenerationally. Ovarian primordial follicle pool size was significantly decreased with all treatments transgenerationally. Differential DNA methylation of the F3 generation sperm promoter epigenome was examined. Differential DNA methylation regions (DMR) were identified in the sperm of all exposure lineage males and found to be consistent within a specific exposure lineage, but different between the exposures. Several genomic features of the DMR, such as low density CpG content, were identified. Exposure-specific epigenetic biomarkers were identified that may allow for the assessment of ancestral environmental exposures associated with adult onset disease. Environmental factors during fetal development can induce a permanent epigenetic change in the germ line (sperm) that then transmits epigenetic transgenerational inheritance of adult-onset disease in the absence of any subsequent exposure. The epigenetic transgenerational actions of various environmental compounds and relevant mixtures were investigated with the use of a pesticide mixture (permethrin and insect repellant DEET), a plastic mixture (bisphenol A and phthalates), dioxin (TCDD) and a hydrocarbon mixture (jet fuel, JP8). After transient exposure of F0 gestating female rats during the period of embryonic gonadal sex determination, the subsequent F1-F3 generations were obtained in the absence of any environmental exposure. The effects on the F1, F2 and F3 generations pubertal onset and gonadal function were assessed. The plastics, dioxin and jet fuel were found to promote early-onset female puberty transgenerationally (F3 generation). Spermatogenic cell apoptosis was affected transgenerationally. Ovarian primordial follicle pool size was significantly decreased with all treatments transgenerationally. Differential DNA methylation of the F3 generation sperm promoter epigenome was examined. Differential DNA methylation regions (DMR) were identified in the sperm of all exposure lineage males and found to be consistent within a specific exposure lineage, but different between the exposures. Several genomic features of the DMR, such as low density CpG content, were identified. Exposure-specific epigenetic biomarkers were identified that may allow for the assessment of ancestral environmental exposures associated with adult onset disease.
Project description:Adult female Wistar rats (about 220g) obtained from a breeding colony were mated and fed either a protein sufficient (PS) or protein restricted (PR) diet (n = 6 per dietary group) during F0 pregnancy which provided an increase in energy of approximately 25% compared to the diet fed to the breeding colony (2018S). During lactation dams were fed AIN93G and litters were standardisied to 8 offspring within 24 hours of birth with a bias towards females. Offpsring were weaned onto AIN93M at postnatal day 28 and F1 and F2 females were mated on postnatal day 70 (n = 6 per F0 dietary group). F1 and F2 dams were fed the PS diet during pregnancy and AIN93G during lactation. Offspring were weaned onto AIN93M. On postnatal day 70 unmated female offspring were fasted for 12 hours then sacrificed for hepatic transcritpome analysis by microarray. Expression of 1,684 genes differed by at least 2 fold between adult female F1 offspring of F0 dams from both dietary groups. 1680 genes were altered in F2 offspring and 2,065 genes altered in F3 offspring. Expression of 113 genes was altered in all three generations. Of these, 47% showed directionally opposite differences between generations. Gene ontology analysis revealed clear differences in the pathways altered in each generation. F1 and F2 offspring of F0 dams fed a PR diet showed impaired fasting glucose homeostasis. Hepatic phosphoenolpyruvate carboxykinase (PEPCK) expression was elevated in F1 and F2 offspring from F0 PR dams, but decreased in F3, compared to PS offspring
Project description:A number of environmental factors (e.g. toxicants) have been shown to promote the epigenetic transgenerational inheritance of disease and phenotypic variation. Transgenerational inheritance requires the germline transmission of altered epigenetic information between generations in the absence of direct environmental exposures. The primary periods for epigenetic programming of the germ line are those associated with primordial germ cell development and subsequent fetal germline development. The current study examined the actions of an agricultural fungicide vinclozolin on gestating female (F0 generation) progeny in regards to the primordial germ cell (PGC) epigenetic reprogramming of the F3 generation (i.e. great-grandchildren). The F3 generation germline transcriptome and epigenome (DNA methylation) were altered transgenerationally. Interestingly, disruptions in DNA methylation patterns and altered transcriptomes were distinct between germ cells at the onset of gonadal sex determination at embryonic day 13 (E13) and after cord formation in the testis at embryonic day 16 (E16). A larger number of DNA methylation abnormalities (epimutations) and transcriptional alterations were observed in the E13 germ cells than in the E16 germ cells. These observations indicate that altered transgenerational epigenetic reprogramming and function of the male germline is a component of vinclozolin induced epigenetic transgenerational inheritance of disease. Insights into the molecular control of germline transmitted epigenetic inheritance are provided. The F0 generation females were exposed to a vehicle (dimethylsulfoxide DMSO) as control or to vinclozolin, as described in the Methods. The F1 generation offspring were bred to generate the F2 generation and the F2 generation offspring were bred to generate the F3 generation offspring. The timed pregnant F2 generation females were used to isolate the F3 generation control and vinclozolin lineage fetal gonads at the E13 and E16 time points. The F3 generation E13 PGC and E16 prospermatogonia were isolated. DNA was isolated from the freshly isolated cells to examine DNA methylation by methylated DNA immunoprecipitation (MeDIP) followed by analysis on a genome-wide promoter tiling array (Chip) using a comparative hybridization MeDIP-Chip analysis between control and vinclozolin lineage samples as described in Methods. This allowed a comparison of the epigenome alterations in F3 vinclozolin lineage germ cells at E13 and E16. Three separate experimental comparisons of control and vinclozolin-lineage animals involving different germ cell isolations were analyzed with three different MeDIP-Chip analyses at each time point.
Project description:Environmental factors during fetal development can induce a permanent epigenetic change in the germ line (sperm) that then transmits epigenetic transgenerational inheritance of adult-onset disease in the absence of any subsequent exposure. The epigenetic transgenerational actions of various environmental compounds and relevant mixtures were investigated with the use of a pesticide mixture (permethrin and insect repellant DEET), a plastic mixture (bisphenol A and phthalates), dioxin (TCDD) and a hydrocarbon mixture (jet fuel, JP8). After transient exposure of F0 gestating female rats during the period of embryonic gonadal sex determination, the subsequent F1-F3 generations were obtained in the absence of any environmental exposure. The effects on the F1, F2 and F3 generations pubertal onset and gonadal function were assessed. The plastics, dioxin and jet fuel were found to promote early-onset female puberty transgenerationally (F3 generation). Spermatogenic cell apoptosis was affected transgenerationally. Ovarian primordial follicle pool size was significantly decreased with all treatments transgenerationally. Differential DNA methylation of the F3 generation sperm promoter epigenome was examined. Differential DNA methylation regions (DMR) were identified in the sperm of all exposure lineage males and found to be consistent within a specific exposure lineage, but different between the exposures. Several genomic features of the DMR, such as low density CpG content, were identified. Exposure-specific epigenetic biomarkers were identified that may allow for the assessment of ancestral environmental exposures associated with adult onset disease. Environmental factors during fetal development can induce a permanent epigenetic change in the germ line (sperm) that then transmits epigenetic transgenerational inheritance of adult-onset disease in the absence of any subsequent exposure. The epigenetic transgenerational actions of various environmental compounds and relevant mixtures were investigated with the use of a pesticide mixture (permethrin and insect repellant DEET), a plastic mixture (bisphenol A and phthalates), dioxin (TCDD) and a hydrocarbon mixture (jet fuel, JP8). After transient exposure of F0 gestating female rats during the period of embryonic gonadal sex determination, the subsequent F1-F3 generations were obtained in the absence of any environmental exposure. The effects on the F1, F2 and F3 generations pubertal onset and gonadal function were assessed. The plastics, dioxin and jet fuel were found to promote early-onset female puberty transgenerationally (F3 generation). Spermatogenic cell apoptosis was affected transgenerationally. Ovarian primordial follicle pool size was significantly decreased with all treatments transgenerationally. Differential DNA methylation of the F3 generation sperm promoter epigenome was examined. Differential DNA methylation regions (DMR) were identified in the sperm of all exposure lineage males and found to be consistent within a specific exposure lineage, but different between the exposures. Several genomic features of the DMR, such as low density CpG content, were identified. Exposure-specific epigenetic biomarkers were identified that may allow for the assessment of ancestral environmental exposures associated with adult onset disease. Methylated sperm DNA was isolated from rats ancestrally exposed to plastics (Bip), vinclozolin (Vip), pesticides (Pip), dioxin (Hip), jet fuel (Jip) or control vehicle (Cip). Three independent samples from each treatment group were obtained. Differential DNA methylation between treatment groups was determined using Nimblegen microarrays. For each treatment, treated samples were paired with control samples and hybridized together on arrays (Bip1/Cip1, Bip2/Cip2, Bip3/Cip3, Vip1/Cip1, etc.), resulting in three arrays per treatment group.