Transcriptional profiling and miRNA-dependent regulatory network analysis of longissimus dorsi muscle during prenatal and adult stages in two distinct pig breeds

MicroRNAs (miRNAs) and mRNAs establish a complex regulatory network influencing diverse biological pathways including muscle development and growth. Elucidating miRNA-dependent regulatory networks involved in muscle development could provide additional insights into muscle traits largely predefined during prenatal development. The present study aimed to determine differentially expressed transcripts and functional miRNA-mRNA relationships associated with different stages of skeletal muscle development in two pig breeds, German Landrace and Pietrain, distinct in muscle characteristics. A comparative transcriptional profiling of longissimus dorsi muscle tissues from fetuses at 35, 63 and 91days post-conception as well as adult pigs (180days postnatum) was performed using the Affymetrix GeneChip porcine genome microarray. Differential expression patterns were identified to be associated with muscularly developmental stages and breed types. The integration of miRNA expression data and ingenuity pathways analysis (ipa) pathway analysis revealed several miRNA-dependent regulatory networks related to muscle growth and development. The present results provide insights into muscle biology for further improvement of porcine meat quality.