Sequence variation of microRNAs and their binding sites in Arabidopsis
Sequence variation of microRNAs and their binding sites in Arabidopsis
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DOI：
10.1104/pp.108.116582
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发表时间：
2008-04-01
期刊：
影响因子：
7.4
通讯作者：
Purugganan, Michael D.
中科院分区：
文献类型：
--
作者：
Ehrenreich, Ian M.;Purugganan, Michael D.
植物和动物之间的主要差异存在于基于microRNA（miRNA）的基因调控的程度和miRNA-信使RNA配对的序列互补性要求两者中。这些差异是否会影响这些位点在分子水平上的进化尚不清楚。为了确定植物物种中miRNA及其靶标的序列变异程度，我们对植物模型拟南芥（Arabidopsis thaliana）中的16个miRNA家族（总共66个miRNA）和这些miRNA的所有52个特征结合位点进行了重新测序，占该物种中已知miRNA和结合位点的约50%。正如先前在人类中所显示的，我们发现与拟南芥中的侧翼序列相比，miRNA及其靶结合位点具有非常低的核苷酸变异和趋异，表明该物种中这些位点上的强纯化选择。然而，成熟miRNA侧翼的序列数据在本研究中表现出正常水平的多态性，并且在某些情况下，非中性进化或对预测的前miRNA二级结构的微妙影响，表明存在用于miRNA等位基因的差异功能的原材料。总的来说，我们的研究结果表明，尽管基于miRNA的调控结构存在差异，但miRNA及其靶点在植物和动物中受到类似的限制。
Major differences exist between plants and animals both in the extent of microRNA (miRNA)-based gene regulation and the sequence complementarity requirements for miRNA-messenger RNA pairing. Whether these differences affect how these sites evolve at the molecular level is unknown. To determine the extent of sequence variation at miRNAs and their targets in a plant species, we resequenced 16 miRNA families (66 miRNAs in total) and all 52 of the characterized binding sites for these miRNAs in the plant model Arabidopsis (Arabidopsis thaliana), accounting for around 50% of the known miRNAs and binding sites in this species. As has been shown previously in humans, we find that both miRNAs and their target binding sites have very low nucleotide variation and divergence compared to their flanking sequences in Arabidopsis, indicating strong purifying selection on these sites in this species. Sequence data flanking the mature miRNAs, however, exhibit normal levels of polymorphism for the accessions in this study and, in some cases, nonneutral evolution or subtle effects on predicted pre-miRNA secondary structure, suggesting that there is raw material for the differential function of miRNA alleles. Overall, our results show that despite differences in the architecture of miRNA-based regulation, miRNAs and their targets are similarly constrained in both plants and animals.