中文摘要：

MicroRNAs（miRNAs）对参与多种生物代谢过程的基因在转录及转录后水平进行负调控。近年来,随着深度测序及芯片技术的应用,有关miRNA的发现和功能分析在植物和动物中得到广泛研究。文章利用第二代测序技术对日本七鳃鳗（Lampetra japonica）白细胞的小RNA进行了高通量测序,共得到5 207 787条小RNA序列,其中4 739 346条序列可以拼接为10 989种mi RNA变体。基于序列相似性分析,发现这10 989个变体序列与306个已知的保守mi RNA家族成员序列相匹配;其中,6个保守miRNA家族成员呈极高丰度表达,表明mi RNA在物种间具有保守性。70个未注释序列被预测为新的miRNA。通过miRNA微阵列技术鉴定与验证了34个新预测的mi RNA在免疫处理的日本七鳃鳗白细胞中表达,其中16个mi RNA前体的最低折叠自由能系数大于0.85,说明日本七鳃鳗存在特异性miRNA。这些物种特异性miRNAs的存在可能在日本七鳃鳗的白细胞生长、发育和对疾病的反应中发挥重要的调控作用。

英文摘要：

MicroRNAs （miRNAs） negatively regulate genes which are involved in various biological processes of metabolism at both transcriptional and post-transcriptional levels. In recent years, the existence and function of miRNAs have been extensively studied in plants and animals with the application of deep sequencing and microarray technology. In this study, small RNAs from leucocytes of Lampetra japonica （L. japonica） were sequenced using the second generation high-throughput sequencing technology. A total of 5 207 787 small RNA sequences were identified, and 4 739 346 of them assembled into 10 989 variants. Based on sequence similarity analysis, the sequences of these variants matched known miRNAs of 306 conserved families, among which 6 conserved miRNA family members ex-pressed at an extremely high level which reflected the conservatism of miRNAs among species. In addition, 70 un-annotated sequences were predicted to be new miRNAs, and 34 of them were further verified expressing in anti-gen-treated L. japonica leucocytes by miRNA microarray assay. Moreover, the minimal folding free energy indexes for 16 of the 34 miRNA precursors exceed 0.85, indicating the existence of species-specific miRNAs in L. japonica which may play important roles in regulating, growth, development and disease response of L. japonica leukocytes.