RESUMEN
Objective : The purpose of the presera study was to devélop a molecular genotyping method test by using a real time PCR hybridization probé and applying it to the analysis of C1843T mutations of the Sus scrofa RYR1 gene. Animáis population Three PSS-susceptible and PSS non-susceptible crossbred swine races were used for the experiments: Pietrain X Landrace Belga, Pietrain X Large White and Pietrain X Duroc. Methods: We have devéloped a genotyping method by using a hybridization probé and applied it to the analysis of C1843T mutations of the RYR1 gene, associated with PSS susceptibility. Genotyping results obtained by hybridization probé strategies were confirmed by restriction analysis and sequencing. In addi-tion, phenotype/genotype correlation analyses were devéloped by using the in vitro contracture test and confirmed the in vivo hálothane-succinylcholine challenge. Results: The real-time PCR with fluorescent hybridization probé methodology was designed to identify ho-mozygous PSS-resistant, PSS-susceptible animáis as well as heterozygous carriers. All cases genotyped by fluorescent hybridization probes were in agreement with PCR restriction enzyme digestión and sequencing and showed a 100% concordance between the in vivo and in vitro porcine stress syndrome (PSS) susceptibility results. Conclusions and clinical relevance: The real-time PCR with fluorescent hybridization probé method described here provides a rapid, easily interpretable and réliáble tool for genotyping the C1843T (Arg615-Cys) polymorphism of the RYR1 gene. This new methodology may be useful in the wide-scale genotyping of PSS-susceptibility and genetic selection.