title: SAGE detects microRNA precursors.
abstract: BACKGROUND
  MicroRNAs (miRNAs) have been shown to play important roles in regulating gene expression. Since miRNAs are often evolutionarily conserved and their precursors can be folded into stem-loop hairpins, many miRNAs have been predicted. Yet experimental confirmation is difficult since miRNA expression is often specific to particular tissues and developmental stages.
  
  
  RESULTS
  Analysis of 29 human and 230 mouse longSAGE libraries revealed the expression of 22 known and 10 predicted mammalian miRNAs. Most were detected in embryonic tissues. Four SAGE tags detected in human embryonic stem cells specifically match a cluster of four human miRNAs (mir-302a, b, c&d) known to be expressed in embryonic stem cells. LongSAGE data also suggest the existence of a mouse homolog of human and rat mir-493.
  
  
  CONCLUSIONS
  The observation that some orphan longSAGE tags uniquely match miRNA precursors provides information about the expression of some known and predicted miRNAs.
authors.affiliation: Center for Functional Genomics, Division of Medical Genetics, Department of Medicine, ENH Research Institute, 1001 University Place, Evanston, IL 60201, USA. xge@northwestern.edu
authors.forename: Xijin
authors.initials: X
authors.lastname: Ge
authors.forename: Qingfa
authors.initials: Q
authors.lastname: Wu
authors.forename: San Ming
authors.initials: SM
authors.lastname: Wang
mesh_terms: D000818:Animals; D002874:Chromosome Mapping; D030541:Databases, Genetic; D053595:Embryonic Stem Cells / Q000737:chemistry; D020869:Gene Expression Profiling / Q000379:methods*; D015723:Gene Library; D006801:Humans; D051379:Mice / Q000196:embryology / Q000235:genetics*; D035683:MicroRNAs / Q000235:genetics*; D009690:Nucleic Acid Conformation; D012322:RNA Precursors / Q000032:analysis* / Q000235:genetics; D014158:Transcription, Genetic
chemical_list: D035683:MicroRNAs; D012322:RNA Precursors