Environmentally Induced Epigenetic Transgenerational Inheritance of Altered SRY Genomic Binding During Gonadal Sex Determination

A critical transcription factor required for mammalian male sex determination is SRY (sex determining region on the Y chromosome). The expression of SRY in precursor Sertoli cells is one of the initial events in testis development. The current study was designed to determine the impact of environmentally induced epigenetic transgenerational inheritance on SRY during gonadal sex determination in the male. The agricultural fungicide vinclozolin and vehicle control (DMSO) exposed gestating females (F0 generation) during gonadal sex determination promoted the transgenerational inheritance of differential DNA methylation in sperm of the F3 generation (great grand-offspring). The fetal gonads in F3 generation males were used to identify potential alterations in SRY binding sites in the developing Sertoli cells. Chromatin immunoprecipitation with an SRY antibody followed by genome-wide promoter tiling array (ChIP-Chip) was used to identify alterations in SRY binding. A total of 81 adjacent oligonucleotide sites and 173 single oligo SRY binding sites were identified to be altered transgenerationally in the Sertoli cell vinclozolin lineage F3 generation males. Observations demonstrate the majority of the previously identified normal SRY binding sites were not altered and the altered SRY binding sites were novel and new additional sites. The chromosomal locations, gene associations and potentially modified cellular pathways were investigated. In summary, environmentally induces epigenetic transgenerational inheritance of germline epimutations appears to alter the cellular differentiation and development of the precursor Sertoli cell SRY binding during gonadal sex determination that influence the developmental origins of adult onset testis disease.SRY（Y染色体性别决定区，sex determining region on the Y chromosome）是调控哺乳动物雄性性别决定的关键转录因子。SRY在前体支持细胞（precursor Sertoli cells）中的表达是睾丸发育的初始事件之一。本研究旨在探究环境诱导的表观遗传跨代遗传（epigenetic transgenerational inheritance）对雄性性腺性别决定（gonadal sex determination）过程中SRY的影响。在性腺性别决定阶段，将农用杀菌剂乙烯菌核利（vinclozolin）与溶剂对照（vehicle control，二甲基亚砜，DMSO）分别暴露于妊娠F0代（F0 generation）雌性个体，可诱导F3代（曾孙代）精子中差异性DNA甲基化的跨代遗传。本研究以F3代雄性个体的胎儿性腺为材料，鉴定发育过程中支持细胞内SRY结合位点的潜在改变。采用SRY抗体进行染色质免疫共沉淀（Chromatin immunoprecipitation，ChIP）后结合全基因组启动子平铺芯片（genome-wide promoter tiling array，ChIP-Chip）技术，以鉴定SRY结合的改变。在乙烯菌核利处理谱系的F3代雄性支持细胞中，共鉴定出81个相邻寡核苷酸位点与173个单寡核苷酸SRY结合位点发生了跨代性改变。研究结果显示，绝大多数已报道的正常SRY结合位点未发生改变，而发生改变的SRY结合位点均为新增的新型位点。本研究还对这些位点的染色体位置、基因关联以及潜在调控的细胞通路进行了探究。综上，环境诱导的生殖系表观突变（germline epimutations）的表观遗传跨代遗传，似乎可通过改变性腺性别决定过程中前体支持细胞的SRY结合相关细胞分化与发育进程，进而影响成年发病睾丸疾病的发育起源。