Cloning and single nucleotide polymorphism (SNP) analysis of bactericidal permeability-increasing (BPI) protein gene in Rongchang pig

摘要

Bactericidal permeability-increasing protein (BPI) plays an important role in host innate immune response. Full-length cDNA sequences of BPI genes of human, bovine, brown rat and mouse but not porcine are available in GenBank with accession numbers of NM_001725, NM_173895, NM_001004079 and NM_177850, respectively. In this study, the 3'- and 5'-RACE followed by sequencing was used to elucidate the full-length cDNA sequence of porcine BPI gene (pbpi) for the first time. One hundred and twenty Rongchang pigs were employed to investigate the single nucleotide polymorphism (SNP) of pbpi by polymerase chain reaction single stranded conformational polymorphism (PCR-SSCP) analysis. Bioinformatics analysis revealed that the cDNA of pbpi contained 1874 nucleotides (GenBank accession no. EF436278), with an open reading frame (ORF) of 1452 bases that encodes a protein of 483 amino acids, flanked by a 5'-untranslated region (UTR) of 95 bases and a 3'-UTR of 327 bases. The cDNA sequence of pbpi displayed a high similarity with those of BPI genes from other organisms. Data from PCR-SSCP analysis showed that an SNP site, G397A (Arg101Gln), in exon 3 and four synonymous SNP sites, T512C, G551T, C563T and G599A, in exon 4 of pbpi were found, with G399, C512, G551, C563 and G599 being dominant in Rongchang pig population. The possible importance of these SNPs was discussed and some important genetic markers for disease resistance may be found in these SNPs.