Epigenome-Wide Association Study for Atrazine Induced Transgenerational Histone Retention Sperm Epigenetic Biomarkers for Disease

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.莠去津（Atrazine）是一种常见的农用除草剂，此前已有研究表明其可促进疾病的表观遗传跨代遗传至后代。本研究采用全表观基因组关联研究（epigenome-wide association study，EWAS）的实验设计，旨在鉴定与跨代精子疾病相关的差异组蛋白保留区域（differential histone retention regions，DHRs）。将妊娠的F0代雌性大鼠在胚胎性腺性别决定期短暂暴露于莠去津，随后在无持续暴露的情况下繁育获得后续的F1、F2及F3代子代。对跨代F3代雄性个体进行疾病评估，并收集其精子用于表观遗传分析。研究在青春期晚期发病的个体中观察到病理症状，涵盖睾丸疾病、前列腺疾病、肾脏疾病、消瘦症候及多种复合疾病。针对各类病理类型，已筛选出足够数量仅罹患单一特定疾病的雄性个体。从罹患特定疾病的1年龄成年动物中分离精子DNA与染色质，通过染色质免疫共沉淀测序（chromatin immunoprecipitation sequencing，ChIP-seq）分析其DHRs。对比罹患与未罹患疾病的跨代F3代雄性个体，以鉴定疾病特异性的表观突变生物标志物。未在所有病理类型中发现共通的DHRs。本研究还鉴定出表观突变的基因关联位点，且发现其与此前已报道的疾病相关基因存在相关性。