Plant Epigenomics, Technical University of Munich, Emil-Ramman-Str. 4, 85354, Freising, Germany.
Plant J. 2024 May;118(3):671-681. doi: 10.1111/tpj.16137. Epub 2023 Mar 3.
F1 hybrids derived from a cross between two inbred parental lines often display widespread changes in DNA methylation patterns relative to their parents. To which extent these changes drive non-additive gene expression levels and phenotypic heterosis in F1 individuals is not fully resolved. Current mechanistic models propose that DNA methylation remodeling in hybrids is the result of epigenetic interactions between parental alleles via small interfering RNA (sRNA). These models have strong empirical support but are limited to genomic regions where the two parental lines differ in DNA methylation status. However, most remodeling events occur in parental regions with similar methylation patterns, and seem to be strongly conditioned by distally acting factors, even in isogenic hybrid systems. The molecular basis of these distal interactions is currently unknown, and will likely emerge as an active area of research in the future. Despite these gaps in our molecular understanding, parental DNA methylation states are statistically associated with heterosis, independent of genetic information, and may serve as biomarkers in crop breeding.
F1 杂种是通过两个近交系亲本杂交产生的，它们的 DNA 甲基化模式相对于亲本通常会发生广泛的变化。这些变化在多大程度上导致 F1 个体中基因表达水平的非加性和表型杂种优势尚未完全解决。目前的机制模型提出，杂种中的 DNA 甲基化重塑是亲本等位基因通过小干扰 RNA（sRNA）之间的表观遗传相互作用的结果。这些模型具有很强的经验支持，但仅限于两个亲本系在 DNA 甲基化状态上存在差异的基因组区域。然而，大多数重塑事件发生在具有相似甲基化模式的亲本区域，并且即使在同基因杂种系统中，似乎也受到远距离作用因子的强烈影响。这些远程相互作用的分子基础目前尚不清楚，未来可能会成为一个活跃的研究领域。尽管我们对分子的理解存在这些差距，但亲本 DNA 甲基化状态与杂种优势相关，与遗传信息无关，并且可能成为作物育种中的生物标志物。
