Experimental evidence indicated that interferon-inducible guanylate-binding proteins (GBPs) are similar with genes in the myxovirus (Mx) resistance protein subfamily of the large GTPases protein family and play important roles in the resistance to intracellular pathogens. As more diseases exert significant influence on pig industry, it is anticipated that more candidate disease-resistance genes could be found in future strategies aimed at improving genetic resistance to infectious diseases. In this study, we cloned cDNA sequences and analyzed the genomic structure of porcine GBP1 (poGBP1) and GBP2 (poGBP2). The two genes were mapped to SSC4q21-q23 and SSC4q24 by the SCHP panel respectively, further IMpRH panel analysis showed both genes were most closely linked to the marker SWR153. The deduced amino acid sequences of these two genes share the same three classical GTP-binding motifs at the amino terminus and are less conserved at the carboxyl termini except for a CaaX motif, compared with human and mouse counterparts. The reverse transcriptase-polymerase chain reaction (RT-PCR) revealed that poGBP1 and poGBP2 were both widely expressed in many tissues, and transient transfection indicated that poGBP1 and poGBP2 proteins were both located in cytoplasms within Pig Kidney Epithelial cells (PK15). Quantitative real-time PCR (Q-RT-PCR) analyses showed poGBP1 and poGBP2 had very similar expression patterns in PK15 cells at different time points after poly I:C stimulation, suggesting that ISRE (interferon-stimulated response element) plays a crucial role in the transcriptional regulation of these two genes. Four single nucleotide polymorphisms (SNPs) and three SNPs were detected in the cDNA sequences of poGBP1 and poGBP2, respectively. Association analyses revealed that the poGBP1 Eco81I and poGBP2 SspI polymorphisms both had significant associations (p<0.05) with red blood cell count (RBC), haemoglobin concentration (HGB) and hematocrit (HCT) of 17-day-old pigs.

The S100A12 gene belongs to the S100 family of genes, which are specific to vertebrates. It is involved in many inflammatory diseases of human and has been considered as a powerful diagnostic gene. In the present study, we identified the porcine S100A12 (pS100A12) gene, provided evidence that pS100A12 is located on chromosome 4 and is closely linked to SW512. We show that pS100A12 is expressed preferentially in immune organs/tissues, e.g., bone marrow, spleen, and inguinal lymph nodes. Expression of the pS100A12 gene is dramatically induced in porcine whole blood cultures by both lipopolysaccharide (LPS) and polyinosine-polycytidylic acid (Poly(I:C)). Elevated expression of pS100A12 is also correlated with in vivo infection with porcine circovirus type 2 (PCV-2) from at least 48h post infection. By analyzing a series of pS100A12 promoter reporter constructs, we have defined two crucial regions (-1013 to -590, -135 to -50) that are responsible for LPS- and Poly(I:C)-induced transcriptional activation, and demonstrated that the LPS/Poly(I:C)-PKC-C/EBPb-pS100A12 pathway may play a critical role in the transcription of the pS100A12.