Study on Differential Expression of PRRSV Receptor Genes in Lung Tissues of Different Breeds of Pig Infected with HP-PRRSV

In order to understand the molecular mechanism of host susceptibility differential to highly pathogenic porcine reproductive and respiratory syndrome (HP-PRRSV) infection among three breeds of pig, Tibetan pig,ZangMei Black and Yorkshire,the mRNA level of five reported PRRSV receptor genes (HSPG2,SIGLEC1,CD163,VIM and NMMHC-ⅡA) expressed in lung were investigated on 0,4, 7 and 14 days post infection (dpi) with HP-PRRSV JXA1 isolate.The Real-time RT-PCR results showed that the expression of HSPG2 in Tibetan pig increased significantly on 4 and 14 dpi and decreased significantly on 7 dpi compared with the expression on 0 dpi (P < 0.05), and its expression in ZangMei Black on 14 dpi was significantly higher than that of on 7 dpi (P < 0.05);An increased expression of SIGLEC1 in Tibetan pig was observed on 4 and 14 dpi (P < 0.05), and a decreased expression of the same gene was detected in Yorkshire on 4,7 and 14 dpi (P < 0.05);The expression of CD163 elevated significantly on 14 dpi in both Tibetan pig and ZangMei Black (P < 0.05), however its expression reduced significantly on 7 and 14 dpi in Yorkshire (P < 0.05); The expression of VIM gene was significantly higher on 7 dpi in Tibetan pig and significantly lower on 7 dpi in Yorkshire (P < 0.05); And the expression of NMMHC-ⅡA was significantly higher on 4 dpi in ZangMei Black, which was also significantly higher in Yorkshire on 4 and 14 dpi (P < 0.05).In conclusion, SIGLEC1 and VIM might be important genes to influence the host resistance of Tibetan pig,ZangMei Black and Yorkshire to HP-PRRSV infection.