The genome sequence of allopolyploid Brassica juncea and analysis of differential homoeolog gene expression influencing selection
The genome sequence of allopolyploid Brassica juncea and analysis of differential homoeolog gene expression influencing selection
复制标题
异源多倍体芥菜基因组序列及影响选择的差异同源基因表达分析
DOI：
10.1038/ng.3657
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发表时间：
2016-10-01
期刊：
影响因子：
30.8
通讯作者：
Zhang, Mingfang
中科院分区：
文献类型：
--
作者：
Yang, Jinghua;Liu, Dongyuan;Zhang, Mingfang
芸苔属包括三个二倍体和三个异源多倍体基因组，但对通过多倍体进化的农业重要性状缺乏明确的认识。采用散弹枪法和单分子读取法对芥菜异源多倍体基因组进行了组装。我们发现芥菜和甘蓝型油菜的A亚基因组各自具有独立的起源。结果表明，芥菜A亚基因组为单系起源，并进化为蔬菜和油料利用亚种。异源多倍体芥菜亚基因组之间存在同源表达优势，差异表达基因比中性基因表现出更大的选择潜力。芥菜属同源基因的优势表达促进了芥子油苷和脂质代谢基因在蔬菜和油脂生产亚品种中的选择。这些同源表达优势关系有助于选择响应，预测多倍体作物基因组选择的方向性效应。
The Brassica genus encompasses three diploid and three allopolyploid genomes, but a clear understanding of the evolution of agriculturally important traits via polyploidy is lacking. We assembled an allopolyploid Brassica juncea genome by shotgun and single-molecule reads integrated to genomic and genetic maps. We discovered that the A subgenomes of B. juncea and Brassica napus each had independent origins. Results suggested that A subgenomes of B. juncea were of monophyletic origin and evolved into vegetable-use and oil-use subvarieties. Homoeolog expression dominance occurs between subgenomes of allopolyploid B. juncea, in which differentially expressed genes display more selection potential than neutral genes. Homoeolog expression dominance in B. juncea has facilitated selection of glucosinolate and lipid metabolism genes in subvarieties used as vegetables and for oil production. These homoeolog expression dominance relationships among Brassicaceae genomes have contributed to selection response, predicting the directional effects of selection in a polyploid crop genome.