Plant Reproductive Genetics, GCOE Research Group, Graduate School of Biological Science, Nara Institute of Science and Technology, Japan.
Plant Cell Physiol. 2012 May;53(5):809-16. doi: 10.1093/pcp/pcs049. Epub 2012 Apr 5.
Genomic imprinting is an epigenetic phenomenon found in mammals and flowering plants that leads to differential allelic gene expression depending on their parent of origin. In plants, genomic imprinting primarily occurs in the endosperm, and it is associated with seed development. The imprinted expression is driven by the epigenetic memory programmed in each lineage of female and male germlines. Several imprinted genes have been identified based on genetic studies in maize and Arabidopsis. Recent advances in genome-wide analyses made it possible to identify multiple imprinted genes including many nuclear proteins, such as transcription factors and chromatin-related proteins in different plant species. Some of these genes are conserved in Arabidopsis, rice and maize, but many are species specific. Genome-wide analyses also clarified the regulation mechanism of imprinted genes orchestrated by DNA methylation and histone methylation marks. Additionally, genetic analyses using Arabidopsis revealed new regulatory factors of DNA demethylation and imprinting and shed light on the more precise mechanisms.
基因组印记是一种在哺乳动物和开花植物中发现的表观遗传现象，导致等位基因的差异表达，这取决于它们的亲本来源。在植物中，基因组印记主要发生在胚乳中，与种子发育有关。印记表达由雌性和雄性生殖系的每个谱系中编程的表观遗传记忆驱动。已经根据玉米和拟南芥的遗传研究鉴定了几个印记基因。最近在全基因组分析方面的进展使得有可能在不同的植物物种中鉴定出多个印记基因，包括许多核蛋白，如转录因子和染色质相关蛋白。这些基因中的一些在拟南芥、水稻和玉米中是保守的，但许多是物种特异性的。全基因组分析还阐明了由 DNA 甲基化和组蛋白甲基化标记协调的印记基因的调控机制。此外，使用拟南芥进行的遗传分析揭示了 DNA 去甲基化和印记的新调节因子，并阐明了更精确的机制。
