Identification Of MicroRNA Related To Porcine Fat Deposition

microRNAs(miRNAs), a class of endogenous small noncoding RNAs with length of 20~25 nt, mediate post transcriptional regulation of protein-coding genes by binding chiefly to the 3’untranslated region of target mRNAs, leading to translational inhibition, mRNA destabilization or degradation. mi RNAs are highly conserved in animal evolution and exhibit spatial and temporal expression patterns and play an integral role in many different biological processes like cell proliferation, differentiation and apoptosis, neurodevelopment, fat metabolism.In this study, liver tissues in different gender pigs were used respectively for sRNA libraries construction including 2 boar and 2 sow. Illumina/Solexa highthrought-sequencing technology was used to investigate the sequences distribution in two libraries, and the sequencing data was statisticed and analyzed through quality control, length distribution and selected out differentially expressed miRNAs. The differentially expressed miRNAs were further analyzed using bioinformatics, including target genes prediction, GO annotation and KEGG pathway analysis.5894364 and 6435206 clean reads were obtained in boar and sow library, respectively, accounted for 54.67% and 60.2% of total reads. Statistical results of sRNA length distribution showed, sRNA sequences were mainly distributed in the range of 21-23 nt, the 22 nt was the most and accounted for 27.32% and 28.78% in two libraries, respectively, followed by 21 nt and 23 nt. The sRNA having different length exhibited differential distribution in two libraries. 167 miRNA were differential expressed between different libraries. Bioinformatics analysis of differential expressed miRNAs showed many pathway were significantly enriched(P <0.05), of which, Regulation of actin cytoskeleton, MAPK signaling pathway, Focal adhesion, Endocytosis, Leukocyte transen dothelial migration, Neurotrophin signaling pathway may be related to fat deposition.The result of qRT-PCR showed ssc-mir-4332、ssc-mir-4338、ssc-miR-127、ssc-mi R-424 are significant down-regulated while ssc-miR-194、ssc-miR-545、ssc-miR-22 were significant up-regulated.The results show that some miRNAs and genes may play an important role in fat deposition. This result will lay the foundation for the further study of regulatory mechanism of miRNAs in fat deposition. At the same time provide a new theoretical basis for the swine genetics and breeding.