Wang Jia-Fu, Zhou Hui, Chen Yue-Qin, Luo Qing-Jun, Qu Liang-Hu
Key Laboratory of Gene Engineering of the Ministry of Education, Biotechnology Research Center, Zhongshan University, Guangzhou 510275, People's Republic of China.
Nucleic Acids Res. 2004 Mar 12;32(5):1688-95. doi: 10.1093/nar/gkh332. Print 2004.
MicroRNAs (miRNAs) are present in both plant and animal kingdoms and represents a growing family of non-coding RNAs. These tiny RNAs act as small guides and direct negative regulations usually in the process of development through sequence complementarity to target mRNAs. Although a large number of miRNAs have been identified from various animals, so far plant miRNA studies have focused mainly on Arabidopsis. Here we describe the identification of 20 miRNAs from a rice cDNA library. All the miRNAs were presumably processed from precursors with stem-loop structures and were positively detected in rice cells from at least one tissue, some of which showed tissue-specific expression. Twenty-three unique rice genes were identified to be feasible targets for seven rice miRNAs, including four members of Scarecrow-like transcription factor, the targets of miR-39 that had been characterized in Arabidopsis. Lacking long complementarity, the regulatory targets of 13 miRNAs remain to be further investigated. A possible mechanism of translational repressor for plant miRNAs that lack perfect complementarity to target mRNAs is discussed.
微小RNA（miRNA）存在于植物和动物界，是一个不断壮大的非编码RNA家族。这些微小RNA充当小向导，通常在发育过程中通过与靶mRNA的序列互补来进行负调控。尽管已从各种动物中鉴定出大量miRNA，但到目前为止，植物miRNA研究主要集中在拟南芥上。在此，我们描述了从水稻cDNA文库中鉴定出20种miRNA。所有这些miRNA可能都是从前体茎环结构加工而来，并在至少一种组织的水稻细胞中得到阳性检测，其中一些表现出组织特异性表达。鉴定出23个独特的水稻基因是7种水稻miRNA的可行靶标，包括稻草人样转录因子的四个成员，它们是在拟南芥中已被鉴定的miR-39的靶标。由于缺乏长互补性，13种miRNA的调控靶标仍有待进一步研究。本文还讨论了植物miRNA对靶mRNA缺乏完美互补性时的一种可能的翻译抑制机制。
