Amphidiploid Brassica juncea contains conserved progenitor genomes
Amphidiploid Brassica juncea contains conserved progenitor genomes
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DOI：
10.1139/gen-43-4-679
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发表时间：
2000-08-01
期刊：
影响因子：
3.1
通讯作者：
Lagercrantz, U
中科院分区：
文献类型：
--
作者：
Axelsson, T;Bowman, CM;Lagercrantz, U
为了对天然双二倍体芥菜的基因组进化进行详细的研究，我们构建了两个基于RFLP(限制性片段长度多态性)标记的连锁图谱，一个来自人工合成的芥菜(一个染色体加倍的种间杂种)与一个天然芥菜品种的杂交，另一个来自两个芥菜品种的杂交。通过在两个杂交组合中使用相同的品种，两个图谱可以明确地整合在一起。在天然×人工合成杂交中，所有座位都表现出亲本等位基因的二倍体遗传，表明芥菜型油菜染色体仅与其A基因组同源物配对，黑菜型油菜染色体也与其B基因组同源物配对。从这两个杂交得到的地图也是完全共线的。此外，这些图谱与使用同一套RFLP探针产生的二倍体祖先种(B.ngra和B.Rapa)的图谱是共线的。这些数据表明，自多倍体形成以来，芥菜的基因组基本保持不变。我们的观察似乎驳斥了多倍体基因组的形成伴随着基因组结构的快速变化的说法。
To perform a detailed study of genome evolution in the natural Brassica amphidiploid B. juncea, we have constructed two linkage maps based on RFLP (restriction fragment length polymorphism) markers; one generated from a cross between a resynthesized B. juncea (a chromosome doubled interspecific B. rapa x B. nigra hybrid) and a natural B. juncea cultivar, the other from a cross between two B. juncea cultivars. By using a common cultivar in both crosses, the two maps could be unambiguously integrated. All loci exhibited disomic inheritance of parental alleles in the natural x resynthesized cross, showing that B. rapa chromosomes paired exclusively with their A-genome homologues in B. juncea and that B. nigra chromosomes likewise paired with their B-genome homologues. The maps derived from the two crosses were also perfectly collinear. Furthermore, these maps were collinear with maps of the diploid progenitor species (B. nigra and B. rapa) produced using the same set of RFLP probes. These data indicate that the genome of B. juncea has remained essentially unchanged since polyploid formation. Our observations appear to refute the suggestion that the formation of polyploid genomes is accompanied by rapid change in genome structure.