title: Global analysis of microRNA target gene expression reveals that miRNA targets are lower expressed in mature mouse and Drosophila tissues than in the embryos.
abstract: MicroRNAs (miRNAs) are non-coding small RNAs of approximately 22 nt that regulate the gene expression by base pairing with target mRNAs, leading to mRNA cleavage or translational repression. It is currently estimated that miRNAs account for approximately 1% of predicted genes in higher eukaryotic genomes and that up to 30% of genes might be regulated by miRNAs. However, only very few miRNAs have been functionally characterized and the general functions of miRNAs are not globally studied. In this study, we systematically analyzed the expression patterns of miRNA targets using several public microarray profiles. We found that the expression levels of miRNA targets are lower in all mouse and Drosophila tissues than in the embryos. We also found miRNAs more preferentially target ubiquitously expressed genes than tissue-specifically expressed genes. These results support the current suggestion that miRNAs are likely to be largely involved in embryo development and maintaining of tissue identity.
authors.affiliation: Mammalian Cell Genetics Group, Biotechnology Research Institute, National Research Council Canada Montreal, Quebec, H4P 2R2, Canada. zhenbao.yu@nrc.ca
authors.forename: Zhenbao
authors.initials: Z
authors.lastname: Yu
authors.forename: Zhaofeng
authors.initials: Z
authors.lastname: Jian
authors.forename: Shi-Hsiang
authors.initials: SH
authors.lastname: Shen
authors.forename: Enrico
authors.initials: E
authors.lastname: Purisima
authors.forename: Edwin
authors.initials: E
authors.lastname: Wang
mesh_terms: D000818:Animals; D004330:Drosophila / Q000196:embryology / Q000235:genetics* / Q000378:metabolism; D004622:Embryo, Mammalian / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000378:metabolism; D047108:Embryonic Development / Q000235:genetics*; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D051379:Mice; D035683:MicroRNAs / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism; D014018:Tissue Distribution
chemical_list: D035683:MicroRNAs; D012333:RNA, Messenger