Transcriptome-wide analysis of microRNA expression in the malaria mosquito Anopheles gambiae
Transcriptome-wide analysis of microRNA expression in the malaria mosquito Anopheles gambiae
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DOI：
10.1186/1471-2164-15-557
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发表时间：
2014-07-04
期刊：
影响因子：
4.4
通讯作者：
Levashina, Elena
中科院分区：
文献类型：
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作者：
Biryukova, Inna;Ye, Tao;Levashina, Elena
背景：microRNA (miRNA) 是一类高度丰富的小非编码调节 RNA，可在多细胞生物中转录后调节基因表达。 miRNA 参与广泛的生物和生理过程，包括调节宿主对微生物感染的免疫反应。关于疟疾冈比亚按蚊中 miRNA 表达的小规模研究已有报道，但迄今为止尚未对 miRNA 进行全面分析。结果：利用小 RNA 测序，我们从头鉴定了冈比亚按蚊在成年糖和血液喂养的雌性中表达的 miRNA 库。我们提供了 123 个 miRNA 的转录证据，其中包括 58 个新发现的 miRNA。在新描述的 miRNA 中，19 个 miRNA 与其他昆虫物种中已知的 miRNA 同源，其中 17 个 miRNA 具有仅限于种子序列的序列相似性。其余 21 个新 miRNA 与已知 miRNA 没有明显的序列同源性。对成熟 miRNA 的详细生物信息学分析揭示了其 5' 端发生的序列变异，并导致超过 5% 的 miRNA 发生功能性种子转移。我们还在成熟 miRNA 的 3' 端检测到显着的序列异质性，这主要是由于不精确的加工和转录后修饰造成的。对换臂事件的比较分析揭示了蚊子吸血诱导的物种特异性显性成熟 miRNA 的产生。我们还鉴定了新的保守且片段化的 miRNA 簇和冈比亚 A. 特异的 miRNA 基因重复。通过 miRNA 表达谱分析，我们在定期喂血后和感染伯氏疟原虫后的早期时间点鉴定了差异表达的 miRNA。在吸血蚊子中检测到 4 个 miRNA 的表达水平发生显着变化，而在伯氏疟原虫感染后，有 6 个 miRNA 的表达水平显着上调。结论：在本研究中，我们对冈比亚蚊子中的 miRNA 进行了首次系统分析。我们提供了关于成熟 miRNA 序列多样性和蚊子 miRNA 进化中功能转变的新见解。我们鉴定了一组差异表达的 miRNA，它们对正常和感染性血粉有反应。按蚊 miRNA 及其亚型的扩展集为冈比亚按蚊 miRNA 表达模式和生物学功能的进一步实验研究提供了基础。
Background: microRNAs (miRNAs) are a highly abundant class of small noncoding regulatory RNAs that post-transcriptionally regulate gene expression in multicellular organisms. miRNAs are involved in a wide range of biological and physiological processes, including the regulation of host immune responses to microbial infections. Small-scale studies of miRNA expression in the malaria mosquito Anopheles gambiae have been reported, however no comprehensive analysis of miRNAs has been performed so far.Results: Using small RNA sequencing, we characterized de novo A. gambiae miRNA repertoire expressed in adult sugar-and blood-fed females. We provided transcriptional evidences for 123 miRNAs, including 58 newly identified miRNAs. Out of the newly described miRNAs, 19 miRNAs are homologs to known miRNAs in other insect species and 17 miRNAs share sequence similarity restricted to the seed sequence. The remaining 21 novel miRNAs displayed no obvious sequence homology with known miRNAs. Detailed bioinformatics analysis of the mature miRNAs revealed a sequence variation occurring at their 5'-end and leading to functional seed shifting in more than 5% of miRNAs. We also detected significant sequence heterogeneity at the 3'-ends of the mature miRNAs, mostly due to imprecise processing and post-transcriptional modifications. Comparative analysis of arm-switching events revealed the existence of species-specific production of dominant mature miRNAs induced by blood feeding in mosquitoes. We also identified new conserved and fragmented miRNA clusters and A. gambiae-specific miRNA gene duplication. Using miRNA expression profiling, we identified the differentially expressed miRNAs at an early time point after regular blood feeding and after infection with the rodent malaria parasite Plasmodium berghei. Significant changes were detected in the expression levels of 4 miRNAs in blood-fed mosquitoes, whereas 6 miRNAs were significantly upregulated after P. berghei infection.Conclusions: In the current study, we performed the first systematic analysis of miRNAs in A. gambiae. We provided new insights on mature miRNA sequence diversity and functional shifts in the mosquito miRNA evolution. We identified a set of the differentially expressed miRNAs that respond to normal and infectious blood meals. The extended set of Anopheles miRNAs and their isoforms provides a basis for further experimental studies of miRNA expression patterns and biological functions in A. gambiae.