Expresses Study And Function Prediction Of MiRNAs Involved In Adipose Tissue Metabolism Of Fat-tailed Sheep

The adipose tissue is the main form of energy storage. However, the fat deposition of meat-type animals too much or too little will affect the meat quality and flavor. Therefore, it is crucial to study on fat metabolism of meat-type animals. At present, function of miRNA in adipose tissue metabolism progress have a lot of research reports of mouse, human, pig and cattle, but less in sheep fat metabolism progress.In this study, miRNA in sheep adipose tissues were sequencing by the high-throughput sequencing technology. Sequencing results were validated and analyzed by stem-loop qRT-PCR technology and bioinformatics methods, for finding specifically expressed and commonly expressed miRNAs in different part of sheep adipose tissue. Three tissue- specifically expressed miRNAs (miR-370-3p, miR-411b-5p and miR329b-5p) and three tissue-commonly expressed miRNAs (miR-143, miR-103 and miR-191)were selected, and subjected to study their expresses spatiotemporally by stem-loop qRT-PCR. Target genes of these six miRNAs were prediction by biology software, and analyzed the KEGG pathway.This study aims to uncover the biological function in fat development progress of sheep. The main results as follows:(1) There are 128 and 112 conserved miRNAs were obtained, and 198 and 196 novel microRNAs were found respectively in perirenal and subcutaneous adipose tissues of Guangling large-tailed sheep. Combined with the previous analysis results of miRNAs detected in tail adipose tissue,12 conserved and 66 novel miRNAs were specifically espressed in perirenal adipose tissue; one conserved and 30 novel miRNAs were specifically espressed in subcutaneous adipose tissue; and one conserved and 34 novel miRNAs were specifically espressed in tail adipose tissue. There were seven in eight PCR results of randomly selected miRNAs were consistent with the sequencing results.(2)These six miRNAs expressed spatiotemporally and differentially in the growth and development progress of adipose tissue of Guang ling large-tailed sheep and Small Tailed Han sheep. In addition to miR-191, breed from different depots significantly influenced the other five miRNAs expression, the differentially expressed between breeds that is associated with germplasm characteristic, and five miRNAs expressions in females were slightly higher than that in males. Months of age from different depots significantly influenced the six miRNAs expression, the differentially expressed between associated with different stages of development, corresponding to different seasons and different nutrient levels. miR-143 and miR-370-3p expressions in deep fat depots (PEF) were higher than superficial fat depots (SUF and TAF), and miR-103, miR-191, miR329b-5p and miR-411b-5p expressions were opposite. Two-way interactions of breed with months of age and tissue with months of age were also significantly.(3) These six miRNAs were predicted there target genes by TargetScan and received 1997 genes. KEGG pathway analysis results showed that these target genes were significantly enriched in fat metabolism or adipocyte differentiation pathway, such as Hedgehog signaling pathway, MAPK signaling pathway, Wnt signaling pathway, mToR and ErbB signaling pathway. This result showed that these miRNAs might regulation the development of sheep adipose tissue through these signaling pathways. In addition, they may played a role in regulation nervous system and reproductive performance through Axon guidance, Neurotrophin signaling pathway, Long-term potentiation, Notch signaling pathway, Endometrial cancer, Prostate cancer and Progesterone-mediated oocyte maturation.In sum up, this study analyzed the high-throughput sequencing results of miRNAs in sheep adipose tissue, and got some specific expression and coexpression miRNAs in different adipose tissue, it enhanced the known miRNAs of sheep. Meanwhile, studied the miRNAs expresses spatiotemporally and predicted their target genes in adipose tissue from different tail-type sheep, analyzed there potential biological function. These results provide scientific bases for further research on the regulation role of miRNAs in sheep adipose tissue.