β-defensins gene expression in tissues of the crossbred and Tibetan pigs

β-defensins are antimicrobial peptides, the antimicrobial spectra of which include gram-positive and gram-negative bacteria, protozoans, some fungi, and enveloped virus. 12 porcine β-defensins(pBD) have been identified. In this study, the expressions of genes pBD-1, 2 and 3 were determined using real-time PCR for Chinese Tibetan pigs and crossbred pigs of 7days old in various tissues. The results showed that expressions of pBD-1 and 3 of Tibetan pigs in most tissues were higher than those of crossbred pigs, but pBD-2 was lower. The higher expression of pBD-1 and 3 might be the direct mechanism by which the Tibetan pigs have higher immunity and disease resistance than crossbred pigs, while the lower expression of pBD-2 may indicate a potential for upregulation upon bacterial infection, but the contribution and mechanism to Tibetan pigs' immunity and disease resistance may differ among pBD-1, 2 and 3 and need a further research.