Plant Cytogenetics and Molecular Biology Group, Institute of Biology, Biotechnology and Environmental Protection, Faculty of Natural Sciences, University of Silesia in Katowice, Katowice 40-032, Poland.
Plant Cytogenetics and Molecular Biology Group, Institute of Biology, Biotechnology and Environmental Protection, Faculty of Natural Sciences, University of Silesia in Katowice, Katowice 40-032, Poland.
Trends Plant Sci. 2023 Jun;28(6):661-672. doi: 10.1016/j.tplants.2023.01.002. Epub 2023 Feb 8.
Nucleolar dominance (ND) is selective epigenetic silencing of 35-48S rDNA loci. In allopolyploids, it is frequently manifested at the cytogenetic level by the inactivation of nucleolar organiser region(s) (NORs) inherited from one or several evolutionary ancestors. Grasses are ecologically and economically one of the most important land plant groups, which have frequently evolved through hybridisation and polyploidisation events. Here we review common and unique features of ND phenomena in this monocot family from cytogenetic, molecular, and genomic perspectives. We highlight recent advances achieved by using an allotetraploid model grass, Brachypodium hybridum, where ND commonly occurs at a population level, and we cover modern genomic approaches that decipher structural features of core arrays of NORs.
核仁优势（ND）是对 35-48S rDNA 基因座的选择性表观遗传沉默。在异源多倍体中，它通常在细胞遗传学水平上表现为从一个或多个进化祖先遗传的核仁组织者区域（NORs）的失活。禾本科植物在生态和经济上是最重要的陆地植物群之一，它们经常通过杂交和多倍体化事件进化。在这里，我们从细胞遗传学、分子和基因组的角度回顾了这个单子叶科中 ND 现象的常见和独特特征。我们强调了使用同源四倍体模式草属杂种（Brachypodium hybridum）取得的最新进展，在这个模型中，ND 通常在群体水平上发生，并且涵盖了用于解析 NOR 核心阵列结构特征的现代基因组方法。
