Microarray-based identification of tomato microRNAs and time course analysis of their response to Cucumber mosaic virus infection

A large number of plant microRNAs (miRNAs) are now documented in the miRBase, among which only 30 are for Solanum lycopersicum (tomato). Clearly, there is a far-reaching need to identify and profile the expression of miRNAs in this important crop under various physiological and pathological conditions. In this study, we used an in situ synthesized custom microarray of plant miRNAs to examine the expression and temporal presence of miRNAs in the leaves of tomato plants infected with Cucumber mosaic virus (CMV). Following computational sequence homology search and hairpin structure prediction, we identified three novel tomato miRNA precursor genes. Our results also show that, in accordance with the phenotype of the developing leaves, the tomato miRNAs are differentially expressed at different stages of plant development and that CMV infection can induce or suppress the expression of miRNAs as well as up-regulate some star miRNAs (miRNA*s) which are normally present at much lower levels. The results indicate that developmental anomalies elicited by virus infection may be caused by more complex biological processes.

血清miRNA表达谱在肝细胞癌中的差异性研究

[目的]探讨肝细胞癌、肝硬化患者与正常人血清miRNA表达水平的差异性;筛选出肝癌中差异较明显的血清miRNA谱。[方法]分别收集4例肝癌患者、3例肝硬化患者和3例同期正常体检人员的血清,采用Qiagen miRNA PCR Array芯片法筛查肝癌、肝硬化患者和正常人差异表达的血清miRNA。[结果]初步筛查出了差异表达的血清miRNA,与正常人比较,以相差2倍为分界,肝癌血清miRNA共128个下调,98个上调;肝硬化血清miRNA共131个下调,74个上调;其中,肝癌和肝硬化患者血清miRNA同时下调的有76个,同时上调的有53个。与肝硬化比较,以相差2倍为分界,肝癌血清miRNA共108个下调,103个上调;结合文献、P值及CT值进一步筛选出差异最有意义的7个与肝癌相关的血清miRNA(miR-373-5p,miR-1290,miR-4516,miR-134-5p,miR-144-5p,miR-125a-5p,miR-126-3p)。[结论]差异表达的miRNA谱与肝癌的发生、发展有一定的相关性。