Genome-Wide Analysis of Parent-of-Origin Allelic Expression in Endosperms of Brassicaceae Species, Brassica rapa
Genome-Wide Analysis of Parent-of-Origin Allelic Expression in Endosperms of Brassicaceae Species, Brassica rapa
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DOI：
10.1093/pcp/pcy178
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发表时间：
2018-08
影响因子：
4.9
通讯作者：
Takanori Yoshida;Takahiro Kawanabe;Yi Bo;R. Fujimoto;A. Kawabe
中科院分区：
文献类型：
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作者：
Takanori Yoshida;Takahiro Kawanabe;Yi Bo;R. Fujimoto;A. Kawabe
在动物和植物中观察到的单亲基因表达被称为基因组印记。基因组印记是一种通过表观遗传修饰如DNA甲基化和组蛋白修饰来调控的表观遗传现象。最近的胚乳转录全基因组研究揭示了物种间印迹基因的快速变化，表明这一现象的灵活性。虽然印迹基因的功能意义和进化趋势仍然不清楚，但可以通过物种间的比较来阐明。在这项研究中，我们分析了白菜，拟南芥的近缘物种的基因组印记模式。与古代A. thaliana和B. rapa，B.芜菁有三重基因组。许多印迹基因，超出了估计的数量以前在其他物种中报道，观察。一些印迹基因在菊科植物中是保守的。我们还观察到快速的分子进化的印迹基因相比，非印迹基因在B。拉帕。特别是种间重叠的印迹基因在胚乳中表现出更快的分子进化和优先表达。这可能意味着少数印迹基因在分化的物种中保留了功能作用，并成为自然选择的目标。
Uniparental gene expression, observed in both animals and plants, is termed genomic imprinting. Genomic imprinting is a well-known epigenetic phenomenon regulated through epigenetic modifications such as DNA methylation and histone modifications. Recent genome-wide studies of endosperm transcription have revealed the rapid change of imprinted genes between species, suggesting the flexibility of this phenomenon. Although the functional significance and evolutionary trends of imprinted genes are still obscure, it can be clarified by inter-species comparisons. In this study, we analyzed the pattern of genomic imprinting in Brassica rapa, a species related to Arabidopsis thaliana. Compared with the ancient karyotype of A. thaliana and B. rapa, B. rapa has a triplicated genome. Many imprinted genes, beyond the estimated number previously reported in other species, were observed. Several imprinted genes have been conserved among species in Brassicaceae. We also observed rapid molecular evolution of imprinted genes compared to non-imprinted genes in B. rapa. Especially, imprinted gene overlapping between species showed more rapid molecular evolution and preferential expression in endosperms. It may imply that a small number of imprinted genes have retained functional roles among diverged species and have been the target of natural selection.