Role of genetic factors in different swine breeds exhibiting varying levels of resistance/susceptibility to PRRSV

•The resistance/susceptibility of different populations and individuals to the same pathogen infection are different. Increase in PRRS resistance or tolerance in pigs will have significant economic and welfare implications for the global swine industry.•Cytokine synthesis and secretion play a vital role in the differential mechanism of PRRS susceptibility among pig breeds.•PRRSV receptor plays a decisive role in the susceptibility of different pig breeds.•One SNP leads to individual/breed differences in susceptibility/resistance to PRRS.•Quantity and relative abundance of gut microbiota influence swine susceptibility to PRRSV. Porcine reproductive and respiratory syndrome (PRRS), caused by the PRRS virus (PRRSV), is an economically significant contagious disease. Traditional approaches based on vaccines or medicines were challenging to control PRRSV due to the diversity of viruses. Different breeds of pigs infected with PRRSV have been reported to have different immune responses. However, due to the complexity of interaction mechanism between host and PRRSV, the genetic mechanism leading to PRRSV susceptibility/resistance in various pig breeds is still unclear. Herein, the role of host genetic components in PRRSV susceptibility is systematically described, and the molecular mechanisms by which host genetic factors such as SNPs, cytokines, receptor molecules, intestinal flora, and non-coding RNAs regulate PRRSV susceptibility/resistance. Therefore, improving the resistance to disease of individual animals through disease-resistance breeding technology is of profound significance for uplifting the sustainable and healthy development of the pig industry.