Project description:Adverse experiences in early life are risk factors for the development of behavioral and physiological symptoms that can lead to psychiatric and cognitive disorders later in life. Some of these symptoms can be transmitted to the offspring, in some cases by non-genomic mechanisms involving germ cells. Using a mouse model of unpredictable maternal separation and maternal stress, we show that postnatal trauma alters coping behaviors in adverse conditions in exposed males when adult and in their adult male progeny. The behavioral changes are accompanied by increased glucocorticoid receptor (GR) expression and decreased DNA methylation of the GR promoter in the hippocampus. DNA methylation is also decreased in sperm cells of exposed males when adult. Transgenerational transmission of behavioral symptoms is prevented by paternal environmental enrichment, an effect associated with the reversal of alterations in GR gene expression and DNA methylation in the hippocampus of the male offspring. These findings highlight the influence of both, negative and positive environmental factors on behavior across generations, and the plasticity of the epigenome across life.
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 while males show increased incidence of kidney disease and an altered sperm epigenome. Here, we employ bisulfite-sequencing to explore the methylation profile of male F3 Sprague-Dawley rats bred through the paternal germ line from F0 dams exposed to a single dose of TCDD (0 or 1000 ng/kg body weight) by oral gavage. We identified multiple significant differentially methylated regions (DMRs) affecting receptor genes, including multiple olfactory receptors, as well as Egfr and Mc5r, typically with increased methylation among the TCDD-exposed lineage relative to control lineage.
Project description:The pre and postnatal environment can affect both an individual’s risk of adult onset metabolic disease and that of subsequent generations. Although animal models and epidemiological data implicate epigenetic inheritance, little is known of the mechanisms involved. In a robust intergenerational model of developmental programming we demonstrate that the nutritional environment experienced in utero by F1 generation embryos alters the DNA methylome of the F1 adult male germ line in a locus-specific manner, without affecting overall methylation levels. Differentially methylated regions are mostly hypomethylated and are enriched in nucleosome retaining regions in adult sperm. A substantial fraction is resistant to early embryo methylation reprogramming, and thus have the potential to alter F2 generation development. Altered expression of transcripts neighbouring differentially methylated regions are evident in tissues of F2 offspring despite lack of persistence of differential methylation. Transmitted methylation variation in the germline at key regulatory loci may therefore contribute to the development of metabolic disease in the subsequent generation. 2 biological replicates of pooled sperm samples for each control (C) or undernutrition (UN) model
Project description:Environmental toxicants have been shown to induce the epigenetic transgenerational inheritance of adult onset disease, including testis disease and male infertility. The exposure of a gestating female during the period of gonadal sex determination has been shown to promote sperm epimutations, differential DNA methylation regions (DMR), that transmit transgenerational disease to subsequent generations. The current study was designed to determine the impact of an altered sperm epigenome on the subsequent development of an adult somatic cell (Sertoli cell) that influences the onset of a specific disease (male infertility). A gestating female rat (F0 generation) was exposed to the agriculture fungicide vinclozolin during gonadal sex determination and then the subsequent F3 generation progeny used for the isolation of Sertoli cells and assessment of testis disease. As previously observed, a spermatogenic cell apoptosis was observed. The Sertoli cells that provide the physical and nutritional support for the spermatogenic cells were isolated and alterations in gene expression examined. Over 400 genes were differentially expressed in the F3 generation control versus vinclozolin lineage Sertoli cells. A number of specific signaling pathways and cellular processes were identified to be transgenerationally altered. One of the key metabolic processes affected was pyruvate/lactate production that is directly linked to spermatogenic cell viability. The Sertoli cell epigenome was also altered with over 100 promoter differential DNA methylation regions (DMR) modified in the vinclozolin F3 generation Sertoli cell. The genomic features and overlap with the sperm DMR were investigated. Observations demonstrate that the transgenerational sperm epigenetic alterations subsequently alters the development of a specific somatic cell (Sertoli cell) epigenome and transcriptome that then has a role in the adult onset disease (male infertility). The environmentally induced epigenetic transgenerational inheritance of testis disease appears to be a component of the molecular etiology of male infertility. Environmental toxicants have been shown to induce the epigenetic transgenerational inheritance of adult onset male infertility. The exposure of a gestating female during the period of gonadal sex determination has been shown to promote sperm epimutations, differential DNA methylation regions (DMR), that transmit transgenerational disease to subsequent generations. The current study was designed to determine the impact of an altered sperm epigenome on the subsequent development of an adult somatic cell (Sertoli cell) that influences the onset of a specific disease (male infertility). A gestating female rat (F0 generation) was exposed to the agriculture fungicide vinclozolin during gonadal sex determination and then the subsequent F3 generation progeny used for the isolation of Sertoli cells and assessment of testis disease. The Sertoli cells provide the physical and nutritional support for the spermatogenic cells in the testis. The F3 generation Sertoli cells have an altered transcriptome and epigenome associated with adult onset testis disease. The environmentally induced epigenetic transgenerational inheritance of Sertoli cell abnormalities appears to be a component of the molecular etiology of male infertility. RNA samples from Sertoli cell of 3 F3-control lineage groups are compared to Sertoli cell of 3 F3-vinclozolin lineage groups
Project description:The male gamete has an immense role in reproduction. Besides contributing one half of the genomic DNA, it contributes important epigenetic information that controls and orchestrates its expression during the early stages of embryo development. Although, DNA methylation is a widely studied epigenetic modification, other epigenetic changes like histone modifications, nucleosome landscape and chromatin compaction are also gaining significant consideration. Sperm chromatin despite being majorly compacted with protamines; strategically retains 2-4% of the genome in nucleosomes. While DNA bases are resilient, epigenetic marks are highly susceptible to reprogramming. Environmental pollutants have been known to affect epigenetic marks and many of those pollutants are known to be xeno-estrogenic. Previous studies using tamoxifen, a Selective Estrogen Receptor Modulator – SERM, has been shown to be associated with post implantation loss and DNA methylation aberration in rats. Also, Cyperoterone acetate (CPA), an antiandrogen, has been shown to induce retention of histone modifications in testis. In this study, we show by MNase-sequencing that systemic hormonal disruption leads to deviation in the nucleosomal localization in spermatozoa at many genes of significance during early embryo development. Thus, environmental pollutants, which are mainly estrogenic or antiandrogenic in nature, may exert epigenetic aberrations in the spermatozoa through hormonal disruption which may lead to severe complications during embryo development or in adult life.
Project description:Previously the agricultural fungicide vinclozolin was found to promote the transgenerational inheritance of sperm differential DNA methylation regions (DMRs) termed epimutations that help mediate this epigenetic inheritance. The current study was designed to investigate the developmental origins of the transgenerational DMRs during gametogenesis. Male control and vinclozolin lineage F3 generation rats were used as a source of embryonic day 16 (E16) prospermatogonia, postnatal day 10 (P10) spermatogonia, and adult pachytene spermatocytes, round spermatids, caput epididymal sperm, and caudal sperm. The DMRs between the control versus vinclozolin lineage samples were determined for each developmental stage. The top 100 statistically significant DMRs for each stage were compared and the developmental origins of the caudal epididymal sperm DMRs were assessed.
Project description:Environmental toxicants have been shown to induce the epigenetic transgenerational inheritance of adult onset disease, including testis disease and male infertility. The exposure of a gestating female during the period of gonadal sex determination has been shown to promote sperm epimutations, differential DNA methylation regions (DMR), that transmit transgenerational disease to subsequent generations. The current study was designed to determine the impact of an altered sperm epigenome on the subsequent development of an adult somatic cell (Sertoli cell) that influences the onset of a specific disease (male infertility). A gestating female rat (F0 generation) was exposed to the agriculture fungicide vinclozolin during gonadal sex determination and then the subsequent F3 generation progeny used for the isolation of Sertoli cells and assessment of testis disease. As previously observed, a spermatogenic cell apoptosis was observed. The Sertoli cells that provide the physical and nutritional support for the spermatogenic cells were isolated and alterations in gene expression examined. Over 400 genes were differentially expressed in the F3 generation control versus vinclozolin lineage Sertoli cells. A number of specific signaling pathways and cellular processes were identified to be transgenerationally altered. One of the key metabolic processes affected was pyruvate/lactate production that is directly linked to spermatogenic cell viability. The Sertoli cell epigenome was also altered with over 100 promoter differential DNA methylation regions (DMR) modified in the vinclozolin F3 generation Sertoli cell. The genomic features and overlap with the sperm DMR were investigated. Observations demonstrate that the transgenerational sperm epigenetic alterations subsequently alters the development of a specific somatic cell (Sertoli cell) epigenome and transcriptome that then has a role in the adult onset disease (male infertility). The environmentally induced epigenetic transgenerational inheritance of testis disease appears to be a component of the molecular etiology of male infertility.
Project description:In previous studies, the pesticide DDT was shown to promote the transgenerational inheritance of sperm differential DNA methylation regions (DMRs), also called epimutations, which can mediate this epigenetic inheritance. In the current study, the developmental origins of the transgenerational DMRs during gametogenesis have been investigated. Male control and DDT lineage F3 generation rats were used to isolate embryonic day 16 (E16) prospermatogonia, postnatal day 10 (P10) spermatogonia, adult pachytene spermatocytes, round spermatids, caput epididymal spermatozoa, and caudal sperm. The DMRs between the control versus DDT lineage samples were determined at each developmental stage. The top 100 statistically significant DMRs at each stage were compared and the developmental origins of the caudal epididymal sperm DMRs were assessed.
Project description:The adverse effects of sleep disorders on male fertility are increasingly concerning. In this study, a rat model of chronic sleep restriction (CSR) was established using the modified multiplatform method. The effects of CSR on the fertility of male rats were evaluated first based on sexual behavior. Serum hormones, including testosterone (T), prolactin (PRL), luteinizing hormone (LH) and follicle-stimulating hormone (FSH), and sperm parameters (concentration, viability, motility, deformation rate) were measured, and testicular histology was analysed by hematoxylin and eosin staining. The transcriptional differences between CSR rats and control rats were detected by RNA sequencing (RNA-Seq), and DNA methylation was then detected by bisulfite sequencing. After the differently expressed genes of CSR rats were sequenced and screened, some representative up- and down-regulated genes were randomly sampled to verify the sequencing results by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). Finally, functional annotations were completed, including gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomic (KEGG) pathway analyses. The results showed that the sexual behavior of CSR rats did not change when compared with control group rats. The sperm concentration, viability and motility of the CSR rats decreased significantly, while the sperm malformation rate increased significantly. In the KEGG pathway analysis database, some specific differentially expressed genes were screened, which are involved in metabolic pathways, inflammation-related pathways, the renin-angiotensin system, etc. However, the aforesaid differentially expressed genes in the testes were not related to their DNA methylation status. CSR could significantly reduce the fertility of male rats, and one of its mechanisms occurs by altering gene expression in the testes, which has nothing to do with their DNA methylation. It was suggested that CSR could cause male infertility by significantly altering the testicular transcriptome.