Integrated analysis of miRNA and mRNA expression profiles in 2-, 6-, and 12-month-old Small Tail Han Sheep ovaries reveals that oar-miR-432 downregulates RPS6KA1 expression

In this study, we selected differentially expressed miRNAs through construcing and analyzing the miRNA expression profile during 2-, 6-, and 12- month-old Small Tail Han Sheep ovaries, which provided a theoretical basis for the study of miRNAs regulating the reproduction of Small Tail Han Sheep. RNASeq techniques were used to perform profile analysis for these ovaries. The results showed that 11, 13 and 19 DE miRNAs were identified in 2- vs 6-, 6- vs 12-, and 2- vs 12-month-old ovaries, respectively. In total, 54, 37, and 198 predicted target genes of DE miRNAs were obtained from these three groups, respectively. GO and KEGG analyses showed that, in 2- vs 6-month-olds, the target genes of DE known sheep miRNAs were involved in 102 GO terms and 7 signaling pathways; in 6- vs 12-month-olds, the target genes of DE known sheep miRNAs were involved in 52 GO terms and 3 signaling pathways; and in 2- vs 12-month-olds, the target genes of DE known sheep miRNAs were involved in 88 GO terms and 6 signaling pathways. Three miR–target regulatory networks were constructed based on these DE miRNA–targets. 9 miRNAs were selected to validate the accuracy of miRNA sequencing data by qRT-PCR. The binding sites of oar-miR-432 with RPS6KA1 was validated by a dual luciferase reporter gene detection system. This is the first integrative analysis of miRNA and mRNA expression profiles in Small Tail Han Sheep ovarian development. These data help elucidate the molecular regulatory mechanisms in sheep ovarian development and identify the biomarkers that influence reproductive performance of Small Tail Han Sheep ewe. Integrated analysis of miRNA and mRNA expression profiles in 2-, 6-, and 12-month-old Small Tail Han Sheep ovaries by RNAseq techniques which reveals that oar-miR-432 downregulates RPS6KA1 expression