Identification of small non-coding RNAs as sperm quality biomarkers for in vitro fertilization

a Composition of sncRNA categories in 87 human sperm samples. b Boxplot of the percentage of tsRNAs, rsRNAs, and miRNAs. The P-value of the Wilcoxon signed-rank test is shown in the plot of rsRNA. H-GQE, high rate of good quality embryos; L-GQE, low rate of good quality embryos. c Heatmap of ten differentially expressed tsRNAs between the two groups (H-GQE and L-GQE). The branching pattern is illustrated using a dendrogram. d A schematic diagram of ten differentially expressed tsRNAs in mature tRNA sequences. tsRNA sequences are highlighted in red. e Bar plot of ten differentially expressed tsRNAs between the two groups. f Principal component analysis (PCA) of the sperm cells in the two groups based on ten differentially expressed tsRNAs. The variation values of PC1 and PC2 are 35.0% and 23.3%, respectively. Points represent PCA scores of individual samples. Circles represent a general characterization of the PCA space occupied by the ten tsRNAs. Sperm samples from the two groups are shown with different colors. g The performance of the support vector machine (SVM) classifier for ten differentially expressed tsRNAs. The area of the receiver operating characteristic curve (AUC) is 0.8716; thus, the classifier is very reliable. TPR: true-positive rate, FPR: false-positive rate. h Bar plot of seven differentially expressed rsRNAs between the two groups. i PCA of sperm cells in the two groups based on seven differentially expressed rsRNAs. The variation values of PC1 and PC2 are 43.0% and 17.9%, respectively. j The performance of the SVM classifier for seven differentially expressed rsRNAs. The AUC is 0.8588. k Bar plot of five differentially expressed miRNAs between the two groups. l PCA of sperm cells in the two groups based on five differentially expressed miRNAs. The variation values of PC1 and PC2 are 47.8% and 20.7%, respectively. m The performance of the SVM classifier for five differentially expressed miRNAs. The AUC is 0.702