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Genetic polymorphism of the 17th exon at porcine RYR1 locus: a new variant in a local Portuguese pig breed demonstrated by SSCP analysis
Author(s) -
BejaPereira,
Vírgilio Bento,
Nuno Ferrand,
Brenig
Publication year - 2001
Publication title -
journal of animal breeding and genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.689
H-Index - 51
eISSN - 1439-0388
pISSN - 0931-2668
DOI - 10.1046/j.1439-0388.2001.00294.x
Subject(s) - single strand conformation polymorphism , biology , exon , breed , locus (genetics) , genetics , ryr1 , genotype , allele , polymorphism (computer science) , microbiology and biotechnology , gene , ryanodine receptor , intracellular
Until 1991, malignant hyperthermia represented a major and important economic loss in modern pork production. It is a recessive autosomal disorder with variable expression that was not known to occur in the local pig breeds from Portugal, Alentejano and Bísaro, prior to outcrossing with commercial breeds. In swine, this disorder is due to a mutation in exon 17 of the ryanodine receptor 1 (RYR1) gene, detectable through the analysis of a restriction fragment length polymorphism. We used this technique to distinguish between resistant (NN), carrier (Nn) and susceptible (nn) genotypes, with the aim of excluding carriers from the breeding programme. We further developed a rapid screening technique on the basis of SSCP (single‐strand conformation polymorphism). Fifteen heterozygous (Nn) individuals were found in our sample of 48 individuals from Bísaro breed using both techniques. The absence of homozygous susceptible pigs suggests that the introduction of this allele into Bísaro breed has been recent. A genetically controlled breeding programme on the basis of our findings should help to secure the future of Bísaro pigs of which few individuals are known to exist. To date, only one mutation was found in the 5′ end of exon 17 of the porcine RYR1 gene. Here we present the frequencies of this mutation and describe a new mutation detected in the Alentejano breed. PCR‐SSCP analysis followed by automatic sequencing allowed the detection of this rare transition (C → T) at nucleotide 1851 of exon 17.