|Smith, Timothy - Tim|
Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 3/30/2007
Publication Date: 7/1/2007
Citation: Smith, T.P.L., McDaneld, T.G., Doumit, M.E., Matukumalli, L.K., Sonstegard, T.S., Coutinho, L.L., Wiedmann, R.T. The role of microRNAs in muscle development. Journal of Animal Science (Suppl. 1):637. 2007
Technical Abstract: The genomes of multicellular eukaryotic organisms encode numerous non-coding RNA (ncRNA) species with a variety of known functions, as well as many whose functions are currently unknown. One class of ncRNA genes produce transcripts that are processed by specific cellular machinery to result in small ~18-22 nucleotide-long micro-RNAs (miRs) that provide a targeting mechanism to direct RNA-protein complexes (RISC) to cognate mRNAs. Association of the RISC complex with mRNA has been shown to control gene expression by inhibiting translation or targeting messenger RNA for degradation. The data on miR expression and activity suggests that a major role for this level of regulation is to provide a mechanism for switching the physiological state of the cell in a rapid fashion, as a single miR may have numerous target genes and may act more rapidly than transcriptional control by silencing mRNA already present in the cell. Tissue-specific miRs have been implicated in control of development, homeostasis, and immune response. Studies in mouse myoblast cell lines have defined significant responses of miR populations during differentiation. Our studies of miR profiles in porcine and bovine satellite cell and fetal muscle samples demonstrate marked similarity, but also significant differences, to the murine system. In addition, miR profiles in fast-growing neonatal muscle and fully mature muscle indicate potential roles for regulation of gene expression throughout the life cycle. Analysis of mRNA coexpression through these developmental stages of muscle growth and maturity begins to provide a picture of the interplay between protein-coding gene expression and regulation at the post-transcriptional level via miRs. The data suggest potentially critical roles for miRs in the switch from proliferation to differentiation, in regulating muscle growth in early life, and in maintaining tissue homeostasis in mature muscle.