Wang XiaOwo, Zhang XueGong, Li YanDa
MOE Key Laboratory of Bioinformatics and Bioinformatics Division, TNLIST / Department of Automation, Tsinghua University, Beijing 100084, China.
Sci China C Life Sci. 2008 Jun;51(6):552-9. doi: 10.1007/s11427-008-0075-z. Epub 2008 May 17.
MicroRNAs (miRNAs) are a class of approximately 22 nt long endogenous non-coding RNAs that play important regulatory roles in diverse organisms. Up to now, little is known about the evolutionary properties of these crucial regulators. Most miRNAs were thought to be phylogenetically conserved, but recently, a number of poorly-conserved miRNAs have been reported and miRNA innovation is shown to be an ongoing process. In this work, through the characterization of an miRNA super family, we studied the evolutionary patterns of miRNAs in vertebrates. Recently generated miRNAs seem to evolve rapidly during a certain period following their emergence. Multiple lineage-specific expansions were observed. Homolgous premiRNAs may produce mature products from the opposite stem arms following tandem duplications, which may have important contribution to miRNA innovation. Our observations of miRNAs' complicated evolutionary patterns support the notion that these key regulatory molecules may play very active roles in evolution.
微小RNA（miRNAs）是一类长度约为22个核苷酸的内源性非编码RNA，在多种生物体中发挥着重要的调节作用。到目前为止，对于这些关键调节因子的进化特性知之甚少。大多数miRNAs被认为在系统发育上是保守的，但最近，已经报道了一些保守性较差的miRNAs，并且miRNA的创新被证明是一个持续进行的过程。在这项工作中，通过对一个miRNA超家族的特征分析，我们研究了脊椎动物中miRNAs的进化模式。最近产生的miRNAs在出现后的某个时期似乎进化得很快。观察到多个谱系特异性扩增。串联重复后，同源前体miRNAs可能从相反的茎臂产生成熟产物，这可能对miRNA的创新有重要贡献。我们对miRNAs复杂进化模式的观察支持了这样一种观点，即这些关键调节分子可能在进化中发挥非常活跃的作用。
