The genes within these two gene mo dules were mainly enriched in the categories of protein metabolic process, cellular meta bolic selleck chemicals process, cellular nitrogen compound metabolic process and pri mary metabolic process . These findings confirmed the report that the LDM is mainly associated with metabolic rate. We also found that two coexpressed gene modules in PMM were significantly negatively correlated with amount of orexin B and the orexin receptor in serum, which are repre sentative indicators for the inflammatory process and the immune system in serum. The genes within these two gene modules were mainly enriched in the categories of the immune system process, inflammatory response, immune response, lymphocyte activation, leukocyte activation, and cellular defense response, which suggests that the PMM is a metabolic risk factor.

This finding is consistent with evidence that shows that the PMM is supplied by venous blood from the lumbar spine and has lymphatics overlying the muscle from nearby intra abdominal organs, making it highly suscep tible to contiguous infection and inflammation from organs such as the colon, appendix, terminal ileum and several intra abdominal structures. Conclusions The analysis presented the gene expression profiles and identified DEGs that may be related to the phenotypic differences in porcine muscles among breeds, between the sexes and the anatomical locations. The results pro vide a basis for further exploration of the molecular process of muscle fiber type formulation, and may also help the further development of biomarkers for import ant economic traits in pigs.

Methods Sample preparation Three females and three males at 210 days old for each of the leaner Landrace pigs, the wild Tibetan pigs and the fatty Rongchang pigs were used in this study as previously described. Animals were hu manely sacrificed, according to the Regulations for the Administration of Affairs Concerning Experimental Animals and approved by the Institutional Animal Care and Use Committee in the College of Animal Science and Technology, Sichuan Agricultural University, Sichuan, China. The longissimus dorsi muscle near the last 3rd or 4th rib and the intermediate section of psoas major muscle were rapidly separated from each carcass. Samples were frozen in liquid nitrogen, and stored at ?80 C until RNA extraction. For more information, please refer to Li et al.

Measurements of skeletal muscle related phenotype Measurements of concentrations of 24 serum circulating indicators of metabolism, myofibre cross sectional area and myofibre ratio are from our previous report based on same individuals. For more information, please refer to Li et al. Total RNA was extracted from 36 samples using TRIzol. RNA was purified and DNase treated using an RNeasy Brefeldin_A column according to the manufac turers instructions.