Rapid changes of microsatellite flanking sequence in the allopolyploidization of new synthesized hexaploid wheat
Rapid changes of microsatellite flanking sequence in the allopolyploidization of new synthesized hexaploid wheat
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DOI：
10.1360/03yc0177
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发表时间：
2004-12-01
期刊：
影响因子：
--
通讯作者：
Zhou, YH
中科院分区：
文献类型：
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作者：
Zhang, LQ;Liu, DC;Zhou, YH
推测DNA序列和基因表达的快速变化发生在异源多倍体形成的早期。本研究利用小麦D基因组的21对特异引物，揭示了新形成的异源多倍体及其供体亲本之间的微卫星差异。结果表明，四倍体小麦与节节麦异源多倍体形成的“休克”过程发生了快速变化。SSR侧翼序列的改变导致新条带的出现或亲本条带的消失。亲本带消失的频率远高于新带的出现频率。亲本带的消失不是随机的。四倍体小麦的缺失频率远高于Ae。Tauschii，即AABB基因组的消失率远高于D基因组。SSR侧翼序列的变化发生在F_1、杂种早期或染色体加倍后。从以上结果可以推测，SSR侧翼序列区域非常活跃，并且在多倍化过程中容易发生变化。这表明SSR侧翼序列在多倍化早期可能具有特殊的生物学功能。多倍化早期的快速和方向性变化可能有助于新形成的异源多倍体的快速进化，并允许不同的基因组协调行动。
It was suggested that the rapid changes of DNA sequence and gene expression occurred at the early stages of allopolyploid formation. In this study, we revealed the microsatellite (SSR) differences between newly formed allopolyploids and their donor parents by using 21 primer sets specific for D genome of wheat. It was indicated that rapid changes had occurred in the "shock" process of the allopolyploid formation between tetraploid wheat and Aegilops tauschii. The changes of SSR flanking sequence resulted in appearance of novel bands or disappearance of parental bands. The disappearance of the parental bands showed much higher frequencies in comparison with that of appearance of novel bands. Disappearance of the parental bands was not random. The frequency of disappearance in tetraploid wheat was much higher than in Ae. tauschii, i. e. the disappearance frequency in AABB genome was much higher than in D genome. Changes of SSR flanking sequence occurred at the early stage of F, hybrid or just after chromosome doubling. From the above results, it can be inferred that SSR flanking sequence region was very active and was amenable to change in the process of polyploidization. This suggested that SSR flanking sequence probably had special biological function at the early stage of ployploidization. The rapid and directional changes at the early stage of polyploidization might contribute to the rapid evolution of the newly formed allopolyploid and allow the divergent genomes to act in harmony.