Genome merger: from sequence rearrangements in triticale to their elimination in wheat-rye addition lines
Genome merger: from sequence rearrangements in triticale to their elimination in wheat-rye addition lines
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DOI：
10.1007/s00122-010-1325-6
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发表时间：
2010-08-01
影响因子：
5.4
通讯作者：
Silva, Manuela
中科院分区：
文献类型：
--
作者：
Bento, Miguel;Gustafson, Perry;Silva, Manuela
在多倍体中已经观察到由于不同基因组适应共同的核环境而导致的遗传和表观遗传修饰。在小黑麦中，已经报道了涉及反转录转座子/微卫星富集区的基因组内序列重组。本研究利用反转录转座子间扩增多态性（IRAP）和反转录转座子微卫星扩增多态性（REMAP）来评估小麦-黑麦异附加系的基因组重排，这些异附加系是通过控制二倍体小黑麦与六倍体小麦回交，然后自交获得的。IRAP和REMAP带谱的比较分析，涉及一套完整的小麦-黑麦附加系，和他们的父母种揭示在这些线的存在下，小麦起源的带在小黑麦缺席，和黑麦起源和小黑麦特有的带的情况。在附加系中不存在的黑麦起源条带在小黑麦X小麦回交（BC）中的存在证明基因组重排事件不是回交的直接结果，而是由BC植物后代中的进一步基因组结构重排引起的。使用从不同的黑麦起源序列设计的引物的PCR实验表明，在小麦黑麦附加系的黑麦起源带的情况下，从序列消除的结果，而不是限制引物退火位点的变化，如在小黑麦中所指出的。与小黑麦相比，在所有7个小麦-黑麦附加系中评估的基因组重组事件的水平表明，在附加系中观察到的不平衡的基因组合并情况诱导了新一轮的基因组重排，这表明渗入到小麦中的黑麦染色质的量越少，基因组重排的结果越大。
Genetic and epigenetic modifications resulting from different genomes adjusting to a common nuclear environment have been observed in polyploids. Sequence restructuring within genomes involving retrotransposon/microsatellite-rich regions has been reported in triticale. The present study uses inter-retrotransposon amplified polymorphisms (IRAP) and retrotransposon microsatellite amplified polymorphisms (REMAP) to assess genome rearrangements in wheat-rye addition lines obtained by the controlled backcrossing of octoploid triticale to hexaploid wheat followed by self-fertilization. The comparative analysis of IRAP and REMAP banding profiles, involving a complete set of wheat-rye addition lines, and their parental species revealed in those lines the presence of wheat-origin bands absent in triticale, and the absence of rye-origin and triticale-specific bands. The presence in triticale x wheat backcrosses (BC) of rye-origin bands that were absent in the addition lines demonstrated that genomic rearrangement events were not a direct consequence of backcrossing, but resulted from further genome structural rearrangements in the BC plant progeny. PCR experiments using primers designed from different rye-origin sequences showed that the absence of a rye-origin band in wheat-rye addition lines results from sequence elimination rather than restrict changes on primer annealing sites, as noted in triticale. The level of genome restructuring events evaluated in all seven wheat-rye addition lines, compared to triticale, indicated that the unbalanced genome merger situation observed in the addition lines induced a new round of genome rearrangement, suggesting that the lesser the amount of rye chromatin introgressed into wheat the larger the outcome of genome reshuffling.