GSE130258
Epigenetic Transgenerational Inheritance of Parent-of-Origin Allelic Transmission of Outcross Pathology and Sperm Epimutations Following Ancestral Toxicant Exposures
Previous observations have demonstrated that the agricultural fungicide vinclozolin and the pesticide DDT (dichlorodiphenyltrichloroethane) induce transgenerational sperm epimutations involving DNA methylation. These two environmental toxicants were used to investigate the impacts of parent-of-origin outcross on the epigenetic transgenerational inheritance of disease. Male and female rats were collected from a paternal outcross (POC) or a maternal outcross (MOC) F4 generation control and exposure lineages for pathology and epigenetic analysis. This model allows the parental allelic transmission of disease and epimutations to be investigated. There was increased pathology incidence in MOC outcross F4 generation male prostate, kidney, obesity and multiple diseases through a maternal allelic transmission. The POC outcross F4 generation female offspring had increase pathology incidence for kidney, obesity and multiple diseases through the paternal allelic transmission. Some disease such as testis or ovarian pathology appear to be transmitted through the combined actions of both male and female alleles. Analysis of the F4 generation sperm epigenomes identified differential DNA methylated regions (DMRs) in a genome-wide analysis. Observations demonstrate that DDT and vinclozolin have the potential to promote the epigenetic transgenerational inheritance of disease and sperm epimutations to the outcross F4 generation in a sex specific and exposure specific manner. Overall design: The experimental design involved a daily transient exposure of gestating female F0 generation rats during embryonic days E8–E14 to 100?mg/kg per day of vinclozolin or 25 mg/kg body weight of DDT in dimethylsulfoxide (DMSO) using intraperitoneal injection. A separate control generation lineage was exposed during days E8–E14 of gestation to vehicle DMSO alone. Six different gestating females from different litters for each control, vinclozolin or DDT lineage were used. The F1 generation offspring were obtained and aged to postnatal 90-day of age and randomly selected males and females from different litters bred within the specific lineage. The F2 generation offspring were obtained and aged to 90?days and similarly bred to unrelated males and females from different litters within the same lineage to generate the F3 generation. The F3 generation offspring were aged to 90 days and males and females from different litters were selected to be outbred with either wild type males or wild type females to generate the F4 paternal outcross (POC) generation and the F4 maternal outcross (MOC) generation. No sibling or cousin breeding was used to avoid any inbreeding artifacts. All the animals were sacrificed at 1 year of age for epididymal sperm collection and histopathology analysis of different tissues. The differential DNA methylated regions (DMRs) between the control versus vinclozolin or DDT lineage male sperm were identified using a methylated DNA immunoprecipitation (MeDIP) followed by DNA next-generation sequencing.