National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China.
Institute of Plant Science Paris-Saclay (IPS2), CNRS, INRAE, University Paris-Saclay, 91405, Orsay, France.
Nat Commun. 2023 Oct 18;14(1):6571. doi: 10.1038/s41467-023-42394-0.
Epigenetic reprogramming occurs during reproduction to reset the genome for early development. In flowering plants, mechanistic details of parental methylation remodeling in zygote remain elusive. Here we analyze allele-specific DNA methylation in rice hybrid zygotes and during early embryo development and show that paternal DNA methylation is predominantly remodeled to match maternal allelic levels upon fertilization, which persists after the first zygotic division. The DNA methylation remodeling pattern supports the predominantly maternal-biased gene expression during zygotic genome activation (ZGA) in rice. However, parental allelic-specific methylations are reestablished at the globular embryo stage and associate with allelic-specific histone modification patterns in hybrids. These results reveal that paternal DNA methylation is remodeled to match the maternal pattern during zygotic genome reprogramming and suggest existence of a chromatin memory allowing parental allelic-specific methylation to be maintained in the hybrid.
在繁殖过程中会发生表观遗传重编程，为早期发育重置基因组。在开花植物中，合子中亲本甲基化重塑的机制细节仍不清楚。在这里，我们分析了水稻杂种合子和早期胚胎发育过程中的等位基因特异性 DNA 甲基化，并表明受精后，父本 DNA 甲基化主要被重塑以匹配母本等位基因水平，这种情况在第一次合子分裂后仍然存在。DNA 甲基化重塑模式支持水稻中合子基因组激活（ZGA）过程中主要偏向母本的基因表达。然而，在球形胚胎阶段，亲本等位基因特异性甲基化重新建立，并与杂种中等位基因特异性组蛋白修饰模式相关。这些结果表明，在合子基因组重编程过程中，父本 DNA 甲基化被重塑以匹配母本模式，并暗示存在一种染色质记忆，允许杂种中亲本等位基因特异性甲基化得以维持。
