Repertoire Of MicroRNA Transcriptome In Porcine Different Skeletal Muscle Tissues Using Deep Sequencing

MicroRNAs (miRNAs) are a large family of-22nucleotide noncoding small RNAs which regulate gene expression at posttranscriptional levels., participate in the regulation of almost every cellular process, such as cell proliferation, differentiation, apoptosis and metabolism. Skeletal muscles such as longissimus doris muscle and psoas major muscle play important roles in metabolic health as well as in meat industry, several expression profile studies concentrate on mRNA levels, but little is known about microRNA transcriptome of different skeleton muscle types. A large number of studies have investigated the miRNAs involved in skeletal muscle development.Here, we present the identification of miRNAs in swine skeletal muscles (longissimus doris muscle and psoas major muscle) using deep sequencing technology. In this study, we investigated the miRNA expression patterns of porcine longissimus doris muscle (LDM) and psoas major muscle (PMM) by Illumina Solexa sequencing technology. Analysis of the sequencing data was performed primarily by using ACGT101-miR, an in-house program for discovering miRNAs from deep sequencing data. The main points are indicated as follows:Using this approach, we identified a total of16.62M (LDM) and18.46M (PMM) counts which produced15.22M and17.52M mappable sequences, respectively. The small RNA sequences distribution mainly ranged from20nt to24nt.695unique miRNA could be observed both in all18autosomes and chromosome X.The chromosome distribution of695unique miRNA, indicating most muscle-expressed miRNA mapped to chromosome X (76miRNA). Furthermore,363out of695unique miRNAs were co-expressed in LDM and PMM libraries, of which193showed significant differences (P<0.01). Muscle-specific miR-1showed high expression levels in both libraries, the designed porcine miRNA array confirmed these results. In addition, GO term and KEGG pathway analysis indicated that the abundant of collagen was one of the most enriched annotations associated with fiber types.Our results give the basic results about biological function of miRNAs in swine skeletal muscles for further study.