Epigenetic regulation of subgenome dominance following whole genome triplication in Brassica rapa
Epigenetic regulation of subgenome dominance following whole genome triplication in Brassica rapa
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DOI：
10.1111/nph.13884
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发表时间：
2016-07-01
期刊：
影响因子：
9.4
通讯作者：
Wang, Xiaowu
中科院分区：
文献类型：
--
作者：
Cheng, Feng;Sun, Chao;Wang, Xiaowu
亚基因组显性是异源多倍体植物在全基因组复制后发现的一种重要现象，即一个亚基因组保留了更多的基因，并对旁系同源基因的高表达拷贝贡献更大。与芜菁全基因组三倍化产生的多拷贝旁系同源基因有关，其亚基因组显性受先前建立的相对稳定的因子调控，然后由B遗传和共享。拉帕品种此外，我们发现了一个偏性分布的TE之间的侧翼区的旁系同源基因。此外，24-nt小RNA靶向TE，并且与个体旁系同源基因对的显性表达呈负相关。在此基础上，我们提出了一个桶假说来解释亚基因组显性和杂种优势。我们的研究结果和假设对于多倍体的进化研究是有价值的，并且可能对大多数物种共同的杂种优势的研究有所启发。
Subgenome dominance is an important phenomenon observed in allopolyploids after whole genome duplication, in which one subgenome retains more genes as well as contributes more to the higher expressing gene copy of paralogous genes.To dissect the mechanism of subgenome dominance, we systematically investigated the relationships of gene expression, transposable element (TE) distribution and small RNA targeting, relating to the multicopy paralogous genes generated from whole genome triplication in Brassica rapa.The subgenome dominance was found to be regulated by a relatively stable factor established previously, then inherited by and shared among B. rapa varieties. In addition, we found a biased distribution of TEs between flanking regions of paralogous genes. Furthermore, the 24-nt small RNAs target TEs and are negatively correlated to the dominant expression of individual paralogous gene pairs. The biased distribution of TEs among subgenomes and the targeting of 24-nt small RNAs together produce the dominant expression phenomenon at a subgenome scale.Based on these findings, we propose a bucket hypothesis to illustrate subgenome dominance and hybrid vigor. Our findings and hypothesis are valuable for the evolutionary study of polyploids, and may shed light on studies of hybrid vigor, which is common to most species.