Figure 4: Temporal expression of caput epididymidal piRNAs. (a) Profiles of temporal sRNA constitution in the caput epididymidis by RNA-seq. (b) Composition of sRNA categories according to their length distributions in each sample. (c) RT-qPCR validation of small RNA-seq data for six piRNAs. Quantitative PCR data are presented as mean ± s.d. from three independent animals. NS: not significant;*P < 0.05;**P < 0.01; Student's t-test. The “snRNA Frag”, “rRNA Frag”, and “mRNA Frag” refer to the RNA fragments derived from snRNAs, rRNAs, and mRNAs, respectively. RT-qPCR: quantitative reverse transcription PCR; s.d.: standard deviation; WT: wild-type; KO: knockout; piRNA: P-element-induced wimpy testis (PIWI)-interacting RNA; snRNA: small nuclear RNA; sno-sRNA: small nuclear RNA-derived small RNA; mito-sRNA: mitochondrial RNA-derived small RNA; tsRNA: tRNA-derived small RNA.