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基因组印迹是指基因依其亲代来源的不同，等位基因呈现出差异表达的一种表观遗传现象。印迹在哺乳动物和显花植物的胚胎或胚及胚胎营养组织(胎盘或胚乳)中都有发现，并有独立趋同进化的倾向，而在植物中发现的印迹绝大多数只存在于胚乳中。就表观遗传机制而言，目前发现的印迹表达主要是受到DNA甲基化、PcG蛋白家族介导的组蛋白修饰和ncRNAs共同作用影响。植物印迹基因的全基因组分析揭示出许多印迹基因定位在转座子和重复序列附近，暗示转座子和重复序列的插入与印迹位点的演化存在相关性。“,”Genomic imprinting, the allele-specific expression of an autosomal gene that is dependent on its parent of origin, has independently evolved in flowering plants and mammals. In both of these organism classes, imprin-ting occurs in embryo as well as in embryo-nourishing tissues---the placenta and the endosperm, respectively. Whereas imprinting is predominantly restricted to the endosperm in plants. In terms of epigenetic mechanisms, imprinted expression is largely controlled by an antagonistic action of DNA methylation, Polycomb group-mediated histone methylation and ncRNAs. Genome-wide analyses of imprinted genes in plants have revealed that many imprinted genes are located in the vicinity of transposon or repeat sequences, implying that transposon insertions are associated with the evolution of imprinted loci.