ABSTRACT: The semen of Small Tail Han Sheep has characteristics of high yield, high density, and good motility. To reveal the key miRNAs, mRNAs and miR-Targets regulatory mechanisms in Small Tail Han Sheep testes development, integrated analysis of miRNA and mRNA expression profiles in 2-, 6-, and 12-month-old testes were investigated by RNA-seq technology and bioinformatics methods. As the results shown: 630, 102, and 322 differentially expressed (DE) mRNAs; 5, 1 and 4 DE known miRNAs; 132, 105 and 24 DE novel miRNAs were identified in 2- vs 6-month-old, 6- vs 12-month-old, and 2- vs 12-month-old testes, respectively. GO and pathway analysis showed: in 2- vs 6-month-old testes, DE mRNAs were mainly involved in sexual maturation process and the DE mRNAs were mainly involved in multiple metabolism and biosynthesis pathways; in 6- vs 12-month-old testes, DE mRNAs were mainly involved in metabolism and translation processes, and the most significant pathway that DE mRNAs involved in was ribosome pathway; in 2- vs 12-month-old testes, DE mRNAs were mainly involved in metabolism and physiological processes, and DE mRNAs were mainly involved in multiple metabolism and biosynthesis pathways. Subsequently, 76, 11 and 1 DE miR-Targets were identified in 2- vs 6-month-old, 2- vs 12-month-old, and 6- vs 12-month-old testes, respectively. 3 miR-Target regulatory networks were constructed based on these miR-Targets, which helped to elucidate the regulatory metabolism in Small Tail sheep testes development. Finally, 6 miRNAs and 7 mRNAs were selected to validate the RNA-seq data by RT-PCR.
