Structural and functional comparative mapping between the Brassica A genomes in allotetraploid Brassica napus and diploid Brassica rapa
Structural and functional comparative mapping between the Brassica A genomes in allotetraploid Brassica napus and diploid Brassica rapa
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DOI：
10.1007/s00122-011-1637-1
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发表时间：
2011-10-01
影响因子：
5.4
通讯作者：
Meng, Jinling
中科院分区：
文献类型：
--
作者：
Jiang, Congcong;Ramchiary, Nirala;Meng, Jinling
甘蓝型油菜(Brassica napus，AACC)是一种重要的油料作物，由二倍体甘蓝型油菜(B.raa，AA)和甘蓝型油菜(Brassica oleracea，CC)融合而成。甘蓝型油菜A基因组的完整基因组序列将很快从甘蓝型油菜基因组测序计划中获得，但目前还不清楚甘蓝型油菜A基因组序列对预测异源四倍体甘蓝型油菜A亚基因组的结构和功能有多大的信息。本文根据甘蓝型油菜细菌人工染色体(BACS)序列定位的遗传图谱，对甘蓝型油菜和甘蓝型油菜A亚基因组进行了结构和功能的比较定位。我们鉴定了A基因组三分之一以上的同线区块所代表的节段性保守；同时，种子品质性状的数量性状基因座的比较图谱发现了两个物种A基因组中具有保守功能的十几个同源区域。然而，在异源四倍体甘蓝型油菜和二倍体甘蓝型油菜之间，也观察到了一些基因组重排事件，如倒位、染色体内和染色体间易位，总共覆盖了A基因组的5%。根据这些结果，甘蓝型油菜和甘蓝型油菜的A基因组在功能上大部分是保守的，但由于甘蓝型油菜和甘蓝型油菜A基因组中的基因组重排，在将甘蓝型油菜的全序列数据应用于甘蓝型油菜时必须谨慎。
Brassica napus (AACC genome) is an important oilseed crop that was formed by the fusion of the diploids B. rapa (AA) and B. oleracea (CC). The complete genomic sequence of the Brassica A genome will be available soon from the B. rapa genome sequencing project, but it is not clear how informative the A genome sequence in B. rapa (A(r)) will be for predicting the structure and function of the A subgenome in the allotetraploid Brassica species B. napus (An). In this paper, we report the results of structural and functional comparative mapping between the A subgenomes of B. napus and B. rapa based on genetic maps that were anchored with bacterial artificial chromosomes (BACs)-sequence of B. rapa. We identified segmental conservation that represented by syntenic blocks in over one third of the A genome; meanwhile, comparative mapping of quantitative trait loci for seed quality traits identified a dozen homologous regions with conserved function in the A genome of the two species. However, several genomic rearrangement events, such as inversions, intra-and inter-chromosomal translocations, were also observed, covering totally at least 5% of the A genome, between allotetraploid B. napus and diploid B. rapa. Based on these results, the A genomes of B. rapa and B. napus are mostly functionally conserved, but caution will be necessary in applying the full sequence data from B. rapa to the B. napus as a result of genomic rearrangements in the A genome between the two species.