Skeletal muscle growth represents one of the main economic traits in pig production. To gain a better understanding
of expressions profile in pig muscle, serial analysis of gene expression (SAGE) was performed
in Longissimus dorsi of two pigs at 3 and 9 months of age. A total of 53,120 long tags were obtained and
sequenced from the four muscle SAGE libraries, representing 17,902 different tags, or putative transcripts,
0.64% (+0.09) of which had a relative expression level higher than 1‰. Overall, a total of 218 tags
were highly expressed and 31 had a frequency higher than 3‰.
Functional characterisation of the expression profiles was performed using Kyoto Encyclopedia of Genes
and Genomes metabolic maps and 139 pathways were identified for swine skeletal muscle. Focal adhesion,
Mitogen-Activated Protein Kinase signalling, oxidative phosphorylation, ribosomal proteins, regulation of
actin cytoskeleton and insulin signalling pathways showed an abundance of genes greater than 1.5% of
all the expressed transcripts. A comparison with human SAGE library indicated no statistical differences
for the frequency of genes involved in these metabolic pathways.
