Differential sensitivity of the Arabidopsis thaliana transcriptome and enhancers to the effects of genome doubling
Differential sensitivity of the Arabidopsis thaliana transcriptome and enhancers to the effects of genome doubling
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DOI：
10.1111/j.1469-8137.2010.03198.x
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发表时间：
2010-01-01
期刊：
影响因子：
9.4
通讯作者：
Comai, Luca
中科院分区：
文献类型：
--
作者：
Pignatta, Daniela;Dilkes, Brian P.;Comai, Luca
两种基本类型的多倍体是已知的：异源多倍体，其中不同亲本染色体组通过祖先杂交和重复组合；自多倍体，来自于同一组染色体的增殖。在自多倍体中，核环境的变化不像异源多倍体那样深刻，因此基因组加倍对基因调控的影响尚不清楚。为了研究自多倍体本身的后果，我们对拟南芥二倍体和自四倍体的三个等效谱系进行了微阵列分析。此外，我们比较了内源增强子元件（增强子陷阱）驱动的转基因GFP基因在16个转基因品系二倍体和同源四倍体中的表达水平。我们预计真正的倍性依赖性变化应该发生在独立衍生的自多倍体谱系中。根据这一标准，我们的微阵列分析检测到与多倍体化相关的变化很少，而增强子陷阱分析显示，25%的测试品系在多个植物生命阶段的GFP表达发生了变化。单株诱捕器上基因的表达受到协调调控，而除单株诱捕器外，内源基因的表达不受影响。与观察到的基因稳定性相反，增强子陷阱对倍性的独特敏感性可能源于作用于陷阱的调控途径比内源基因更低的复杂性。
P>Two fundamental types of polyploids are known: allopolyploids, in which different parental chromosome sets were combined by ancestral hybridization and duplication; and autopolyploids, which derive from multiplication of the same chromosome set. In autopolyploids, changes to the nuclear environment are not as profound as in allopolyploids, and therefore the effects of genome doubling on gene regulation remain unclear.To investigate the consequences of autopolyploidization per se, we performed a microarray analysis in three equivalent lineages of matched diploids and autotetraploids of Arabidopsis thaliana. Additionally, we compared the expression levels of GFP transgenes driven by endogenous enhancer elements (enhancer traps) in diploids and autotetraploid of 16 transgenic lines.We expected that true ploidy-dependent changes should occur in independently derived autopolyploid lineages. By this criterion, our microarray analysis detected few changes associated with polyploidization, while the enhancer-trap analysis revealed altered GFP expression at multiple plant life stages for 25% of the lines tested. Genes on individual traps were coordinately regulated while endogenous gene expression was not affected except for one line.The unique sensitivity of enhancer traps to ploidy, in contrast to the observed stability of genes, could derive from lower complexity of regulatory pathways acting on traps versus endogenous genes.