Author:
Boddicker Nicholas J,Bjorkquist Angelica,Rowland Raymond RR,Lunney Joan K,Reecy James M,Dekkers Jack CM
Abstract
Abstract
Background
Host genetics has been shown to play a role in porcine reproductive and respiratory syndrome (PRRS), which is the most economically important disease in the swine industry. A region on Sus scrofa chromosome (SSC) 4 has been previously reported to have a strong association with serum viremia and weight gain in pigs experimentally infected with the PRRS virus (PRRSV). The objective here was to identify haplotypes associated with the favorable phenotype, investigate additional genomic regions associated with host response to PRRSV, and to determine the predictive ability of genomic estimated breeding values (GEBV) based on the SSC4 region and based on the rest of the genome. Phenotypic data and 60 K SNP genotypes from eight trials of ~200 pigs from different commercial crosses were used to address these objectives.
Results
Across the eight trials, heritability estimates were 0.44 and 0.29 for viral load (VL, area under the curve of log-transformed serum viremia from 0 to 21 days post infection) and weight gain to 42 days post infection (WG), respectively. Genomic regions associated with VL were identified on chromosomes 4, X, and 1. Genomic regions associated with WG were identified on chromosomes 4, 5, and 7. Apart from the SSC4 region, the regions associated with these two traits each explained less than 3% of the genetic variance. Due to the strong linkage disequilibrium in the SSC4 region, only 19 unique haplotypes were identified across all populations, of which four were associated with the favorable phenotype. Through cross-validation, accuracies of EBV based on the SSC4 region were high (0.55), while the rest of the genome had little predictive ability across populations (0.09).
Conclusions
Traits associated with response to PRRSV infection in growing pigs are largely controlled by genomic regions with relatively small effects, with the exception of SSC4. Accuracies of EBV based on the SSC4 region were high compared to the rest of the genome. These results show that selection for the SSC4 region could potentially reduce the effects of PRRS in growing pigs, ultimately reducing the economic impact of this disease.
Publisher
Springer Science and Business Media LLC
Subject
Genetics,Animal Science and Zoology,General Medicine,Ecology, Evolution, Behavior and Systematics
Reference19 articles.
1. Kimman TG, Cornelissen LA, Moormann RJ, Rebel JMJ, Stockhofe-Zurwieden N: Challenges for porcine reproductive and respiratory syndrome virus (PRRSV) vaccinology. Vaccine. 2009, 27: 3704-3718. 10.1016/j.vaccine.2009.04.022.
2. Boddicker NJ, Waide EH, Rowland RRR, Lunney JK, Garrick DJ, Reecy JM, Dekkers JCM: Evidence for a major QTL associated with host response to porcine reproductive and respiratory syndrome virus challenge. J Anim Sci. 2012, 90: 1733-1746. 10.2527/jas.2011-4464.
3. Boddicker NJ, Garrick DJ, Rowland RRR, Lunney JK, Reecy JM, Dekkers JCM: Validation and further characterization of a major quantitative locus associated with host response to experimental infection with porcine reproductive and respiratory syndrome virus. Anim Genet. 2013, in press
4. Lunney JK, Steibel JP, Reecy JM, Fritz E, Rothschild MF, Kerrigan M, Trible B, Rowland RRR: Probing genetic control of swine responses to PRRSV infection: current progress of the PRRS host genetics consortium. BMC Proc. 2011, 5: S30-
5. Fang Y, Schneider P, Zhang WP, Faaberg KS, Nelson EA, Rowland RRR: Diversity and evolution of a newly emerged North American Type 1 porcine arterivirus: Analysis of isolates collected between 1999 and 2004. Arch Virol. 2007, 152: 1009-1017. 10.1007/s00705-007-0936-y.