title: Using a kernel density estimation based classifier to predict species-specific microRNA precursors.
abstract: BACKGROUND
  MicroRNAs (miRNAs) are short non-coding RNA molecules participating in post-transcriptional regulation of gene expression. There have been many efforts to discover miRNA precursors (pre-miRNAs) over the years. Recently, ab initio approaches obtain more attention because that they can discover species-specific pre-miRNAs. Most ab initio approaches proposed novel features to characterize RNA molecules. However, there were fewer discussions on the associated classification mechanism in a miRNA predictor.
  
  
  RESULTS
  This study focuses on the classification algorithm for miRNA prediction. We develop a novel ab initio method, miR-KDE, in which most of the features are collected from previous works. The classification mechanism in miR-KDE is the relaxed variable kernel density estimator (RVKDE) that we have recently proposed. When compared to the famous support vector machine (SVM), RVKDE exploits more local information of the training dataset. MiR-KDE is evaluated using a training set consisted of only human pre-miRNAs to predict a benchmark collected from 40 species. The experimental results show that miR-KDE delivers favorable performance in predicting human pre-miRNAs and has advantages for pre-miRNAs from the genera taxonomically distant to humans.
  
  
  CONCLUSIONS
  We use a novel classifier of which the characteristic of exploiting local information is particularly suitable to predict species-specific pre-miRNAs. This study also provides a comprehensive analysis from the view of classification mechanism. The good performance of miR-KDE encourages more efforts on the classification methodology as well as the feature extraction in miRNA prediction.
authors.affiliation: Department of Electrical Engineering, National Cheng Kung University, Tainan, 70101, Taiwan, R.O.C. darby@ee.ncku.edu.tw
authors.forename: Darby Tien-Hao
authors.initials: DT
authors.lastname: Chang
authors.forename: Chih-Ching
authors.initials: CC
authors.lastname: Wang
authors.forename: Jian-Wei
authors.initials: JW
authors.lastname: Chen
mesh_terms: D000465:Algorithms; D001185:Artificial Intelligence; D019295:Computational Biology / Q000379:methods*; D005786:Gene Expression Regulation; D006801:Humans; D035683:MicroRNAs / Q000378:metabolism*; D015233:Models, Statistical; D010363:Pattern Recognition, Automated; D012313:RNA / Q000737:chemistry; D015203:Reproducibility of Results; D016415:Sequence Alignment / Q000379:methods; D012984:Software; D013045:Species Specificity
chemical_list: D035683:MicroRNAs; D012313:RNA