Discovering Numerical Differences between Animal and Plant microRNAs

Previous studies have confirmed that there are many differences between animal and plant microRNAs (miRNAs), and that numerical features based on sequence and structure can be used to predict the function of individual miRNAs. However, there is little research regarding numerical differences between animal and plant miRNAs, and whether a single numerical feature or combination of features could be used to distinguish animal and plant miRNAs or not. Therefore, in current study we aimed to discover numerical features that could be used to accomplish this. We performed a large-scale analysis of 132 miRNA numerical features, and identified 17 highly significant distinguishing features. However, none of the features independently could clearly differentiate animal and plant miRNAs. By further analysis, we found a four-feature subset that included helix number, stack number, length of pre-miRNA, and minimum free energy, and developed a logistic classifier that could distinguish animal and plant miRNAs effectively. The precision of the classifier was greater than 80%. Using this tool, we confirmed that there were universal differences between animal and plant miRNAs, and that a single feature was unable to adequately distinguish the difference. This feature set and classifier represent a valuable tool for identifying differences between animal and plant miRNAs at a molecular level.