Recently, the identification of miRNA targets has received much attention. The strategies to determine miRNA targets include bioinformatic prediction and experimental assays. The bioinformatic prediction methods are mainly based on the confirmed rules of interaction between miRNAs and their targets, and are carried out by programs, such as miRanda, TargetScan, TargetScanS, RNAhybrid, DIANA-microT, PicTar, RNA22 and FindTar, which follow well-known principles. The experimental assays to find miRNA targets employ immunoprecipitation of AGO proteins to identify interacting mRNAs, or the analysis of mRNA or protein levels to identify genes which can be regulated by miRNAs. The improvement of current bioinformatic and experimental assays and the development of novel assays will enable greater efficiency in the identification of miRNA targets and thus facilitate miRNA research. This paper describes progress in the prediction and identification of miRNA targets.
XIA Wei, CAO GuoJun & SHAO NingSheng· Beijing Institute of Basic Medical Sciences, Beijing 100850
From a specialized cDNA library, four novel box H/ACA snoRNAs, named GLsR22, GLsR23, GLsR24 and GLsR25, were identified from the primitive eukaryote, Giardia lamblia. Bioinformat- ics analyses indicated that all of them can be poten- tially folded into double hairpins, the typical secon- dary structures of box H/ACA snoRNAs. GLsR24 and GLsR25 are predicted to guide the site-specific pseudouridylation at U1753 and U2396 on 23S rRNA, respectively, while GLsR22 and GLsR23 belong to the family of “orphan” snoRNAs. All of the four novel snoRNAs are encoded by single copy genes and located in small intergenic regions. Interestingly, compared with the counterparts previously reported in Archaea and other unicellular protozoan, the box H/ACA snoRNAs identified from G. lamblia have unique structural features, implying that snoRNAs evolved from prokaryotes to eukaryotes in different ways.
LUO Jun ZHOU Hui CHEN Chongjian LI Yan CHEN Yueqin QU Lianghu
