Characterization of porcine MMP-2 and its association with immune traits.

Matrix metalloproteinase-2 (MMP-2) plays important roles in inflammation and immunity besides its basic role in degrading and remodelling extracellular matrix (ECM). The expression of MMP-2 is up-regulated in many human as well as animal models of inflammatory and immune diseases. In this study, we cloned the 5'-upstream sequence, 3'-downstream sequence as well as other missed genomic sequences of porcine MMP-2, the genomic structure and the promotor sequence were analyzed and found to share high similarity with those of human MMP-2. Porcine MMP-2 was assigned to SSC6p14-p15, and closely linked to microsatellite SW1108 (53cR, LOD score 7.59) by IMpRH panel. Real-time PCR analysis revealed that the expression of porcine MMP-2 was remarkably different in diverse tissues, a high level expression was observed in the testis and uterus, relatively low expression in other tissues. Allele frequencies determination in different pig breeds and association study were performed on the selected SNP and indel. The results showed that the SNP AcyI in exon 12 was significantly associated with white blood cell count (WBC) of neonate piglets at 0 day (P=0.0079), and classical swine fever virus antibody level (CSFV-AB) of pigs at 17 days (P=0.0461), the indel MspI in intron 4 had remarkable correlation with mean corpuscular hemoglobin (MCH) of pigs at 17 days (P<0.0001).