It has been reported that the muscle-specific isoform （type M, PGAM2） of phosphoglycerate mutase （PGAM） is a housekeeping enzyme; it catalyzes the conversion of 3-phosphoglycerate into 2-phosphoglycerate in the glycolysis process to release energy. It is encoded by the Pgam2 gene. In this study, the cDNA of the porcine Pgam2 was cloned. This gene contains an open reading frame of 765 bp encoding a protein of 253 residues, and the predicted protein sequences share high similarity with other mammalians, 96% identity with humans, and 94% identity with mouse and rats. Pgam2 was mapped to SSC18q13-q21 by the RH panel. In this region, there are several QTLs, such as fat ratio, lean percentage, and diameter of muslce fiber, which affect meat production and quality. The reverse transcriptase-polymerase chain reaction revealed that the porcine Pgam2 gene was mainly expressed in the muscle tissue （skeletal muscle and cardiac muscle）, and was expressed highly at skeletal muscle development stages （embryonic periods： 33, 65, and 90 days post-conception （dpo）; postnatal pigs： 4 days and adult）. This indicates that the Pgam2 gene plays an important role in muscle growth and development. In addition, it was demonstrated that PGAM2 locates both in cytoplasm and nuclei, and takes part in the glycometabolism process of cytoplasm and nuclei.
Haifang QiuShuhong ZhaoXuewen XuMartine YerleBang Liu
In this study, five immune traits including immunoglobulin G （IgG）, delayed-type hypersensitivity （DTH）, leukocyte counts （WBC）, total erythrocytes （RBC） and total protein in serum （TP） were measured in Tongcheng pigs, Swedish Landrace, British Large White and two three-way crossbreds of Landrace× （Large White×Tongcheng）, Large White×（Swedish Landrace×Tongcheng）. Tongcheng pigs had the highest values of IgG （45.04 mg/mL）,DTH （8.87mm）,RBC (7.05×1012/L) and TP （66.69 g/L） among these five pig populations. RBC had positive heterosis in these studied pigs and other four immune traits had negative heterosis. There were significantly positive correlation between IgG and DTH （r=0.33, P<0.01）, IgG and TP （r=0.27, P<0.01）, DTH and TP （r=0.25, P<0.01）.
