Background

While some genetically modified organisms (GMOs) are created to produce new double-stranded RNA molecules (dsRNA), in others, such molecules may occur as an unintended effect of the genetic engineering process. Furthermore, GMOs might produce naturally occurring dsRNA molecules in higher or lower quantities than its non-transgenic counterpart. This study is the first to use high-throughput technology to characterize the miRNome of commercialized GM maize events and to investigate potential alterations in miRNA regulatory networks.

Results

Thirteen different conserved miRNAs were found to be dys-regulated in GM samples. The insecticide Bt GM variety had the most distinct miRNome. These miRNAs target a range of endogenous transcripts, such as transcription factors and nucleic acid binding domains, which play key molecular functions in basic genetic regulation. In addition, we have identified 20 potential novel miRNAs with target transcripts involved in lipid metabolism in maize. isomiRs were also found in 96 conserved miRNAs sequences, as well as potential transgenic miRNA sequences, which both can be a source of potential off-target effects in the plant genome. We have also provided information on technical limitations and when to carry on additional in vivo experimental testing.

Conclusions

These findings do not reveal hazards per se but show that robust and reproducible miRNA profiling technique can strengthen the assessment of risk by detecting any new intended and unintended dsRNA molecules, regardless of the outcome, at any stage of GMO development.

中文翻译：

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系统性 miRNA 分析揭示了转基因玉米代谢中的差异 microRNA。

背景

虽然一些转基因生物 (GMO) 是为了产生新的双链 RNA 分子 (dsRNA) 而创建的，但在另一些情况下，此类分子可能会作为基因工程过程的意外影响而发生。此外，与非转基因对应物相比，转基因生物可能产生更高或更低数量的天然 dsRNA 分子。该研究首次使用高通量技术来表征商业化转基因玉米事件的 miRNA 组，并研究 miRNA 调控网络的潜在改变。

结果

发现 13 种不同的保守 miRNA 在 GM 样品中失调。杀虫剂 Bt GM 品种具有最明显的 miRNome。这些 miRNA 靶向一系列内源性转录物，例如转录因子和核酸结合结构域，它们在基本遗传调控中发挥关键分子功能。此外，我们已经确定了 20 种潜在的新型 miRNA，其靶转录物参与玉米的脂质代谢。在 96 个保守的 miRNA 序列以及潜在的转基因 miRNA 序列中也发现了 isomiR，它们都可能是植物基因组中潜在脱靶效应的来源。我们还提供了有关技术限制以及何时进行额外的体内实验测试的信息。

结论

这些发现并没有揭示危害本身，但表明稳健和可重复的 miRNA 分析技术可以通过在转基因生物开发的任何阶段检测任何新的预期和非预期 dsRNA 分子来加强风险评估，无论结果如何。