Molecular Toxicology Interdepartmental Program, University of California, Los Angeles, Los Angeles, CA 90095, USA.
Human Genetics and Genomic Analysis Training Program, University of California, Los Angeles, Los Angeles, CA 90095, USA.
Cell Rep. 2018 May 22;23(8):2392-2404. doi: 10.1016/j.celrep.2018.04.078.
How artificial environmental cues are biologically integrated and transgenerationally inherited is still poorly understood. Here, we investigate the mechanisms of inheritance of reproductive outcomes elicited by the model environmental chemical Bisphenol A in C. elegans. We show that Bisphenol A (BPA) exposure causes the derepression of an epigenomically silenced transgene in the germline for 5 generations, regardless of ancestral response. Chromatin immunoprecipitation sequencing (ChIP-seq), histone modification quantitation, and immunofluorescence assays revealed that this effect is associated with a reduction of the repressive marks H3K9me3 and H3K27me3 in whole worms and in germline nuclei in the F3, as well as with reproductive dysfunctions, including germline apoptosis and embryonic lethality. Furthermore, targeting of the Jumonji demethylases JMJD-2 and JMJD-3/UTX-1 restores H3K9me3 and H3K27me3 levels, respectively, and it fully alleviates the BPA-induced transgenerational effects. Together, our results demonstrate the central role of repressive histone modifications in the inheritance of reproductive defects elicited by a common environmental chemical exposure.
人工环境线索如何在生物学上被整合并跨代遗传仍知之甚少。在这里,我们研究了模型环境化学物质双酚 A 在秀丽隐杆线虫中引起生殖结果的遗传机制。我们表明,双酚 A(BPA)暴露会导致生殖系中一个表观遗传沉默的转基因在 5 代中去抑制,而与祖先的反应无关。染色质免疫沉淀测序(ChIP-seq)、组蛋白修饰定量和免疫荧光分析表明,这种效应与整个蠕虫和 F3 生殖系核中抑制性标记 H3K9me3 和 H3K27me3 的减少有关,还与生殖功能障碍有关,包括生殖系细胞凋亡和胚胎致死。此外,靶向 Jumonji 去甲基化酶 JMJD-2 和 JMJD-3/UTX-1 分别恢复 H3K9me3 和 H3K27me3 水平,并完全缓解 BPA 诱导的跨代效应。总之,我们的结果表明,在常见环境化学物质暴露引起的生殖缺陷遗传中,抑制性组蛋白修饰起着核心作用。