title: Validation and characterization of Citrus sinensis microRNAs and their target genes.
abstract: BACKGROUND
  MicroRNAs play vital role in plant growth and development by changeable expression of their target genes with most plant microRNAs having perfect or near-perfect complementarities with their target genes but miRNAs in Citrus sinensis (csi-miRNAs) and their function have not been widely studied.
  
  
  RESULTS
  In this study, 15 potential microRNAs in Citrus sinensis (csi-miRNAs) were identified and bioinformatically validated using miR-RACE, a newly developed method for determination of miRNAs prediction computationally. The expression of these fifteen C. sinensis miRNAs can be detected in leaves, stems, flowers and fruits of C. sinensis by QRT-PCR with some of them showed tissue-specific expression. Six potential target genes were identified for six csi-miRNAs and also experimentally verified by Poly (A) polymerase -mediated 3' rapid amplification of cDNA ends (PPM-RACE) and RNA ligase-mediated 5' rapid amplification of cDNA ends (RLM-RACE) which mapped the cleavage site of target mRNAs and detected expression patterns of cleaved fragments that indicate the regulatory function of the miRNAs on their target genes.
  
  
  CONCLUSIONS
  Our results confirm that small RNA-mediated regulation whereby all csi-miRNAs regulate their target genes by degradation.
authors.affiliation: College of Horticulture, Nanjing Agricultural University, 1 Weigang, Nanjing 210095, China.
authors.forename: Changnian
authors.initials: C
authors.lastname: Song
authors.forename: Mingliang
authors.initials: M
authors.lastname: Yu
authors.forename: Jian
authors.initials: J
authors.lastname: Han
authors.forename: Chen
authors.initials: C
authors.lastname: Wang
authors.forename: Hong
authors.initials: H
authors.lastname: Liu
authors.forename: Yanping
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jinggui
authors.initials: J
authors.lastname: Fang
mesh_terms: D032084:Citrus sinensis / Q000235:genetics*; D019295:Computational Biology; D003198:Computer Simulation; D018506:Gene Expression Regulation, Plant; D035683:MicroRNAs / Q000378:metabolism*; D008957:Models, Genetic; D021141:Nucleic Acid Amplification Techniques / Q000379:methods; D011062:Polynucleotide Adenylyltransferase / Q000378:metabolism; D011130:RNA Ligase (ATP) / Q000378:metabolism; D018749:RNA, Plant / Q000378:metabolism*; D015203:Reproducibility of Results; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017423:Sequence Analysis, RNA
chemical_list: D035683:MicroRNAs; D018749:RNA, Plant; D011062:Polynucleotide Adenylyltransferase; D011130:RNA Ligase (ATP)