• Korean Journal of Veterinary Research
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• v.42 no.1
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• pp.65-71
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• 2002

We have utilized the PCR-RFLP method to detect the ryanodine receptor(RYR1) gene mutation and to estimate the genotype frequencies of the RYR1 gene in commercial crossbred pig population. The exon region(659bp) including point mutation(C ${\rightarrow}$T; Arg ${\rightarrow}$Cys) in the porcine ryanodine receptor gene, which is a causal mutation for PSS, was amplified by PCR and digested with Cfo I restriction enzyme. The RYR1 gene was classified into three genotypes by agarose gel electrophoresis. The normal homozygous(NN) individuals showed two DNA fragments consisted of 493 and 166bp. The mutant homozygous(nn) individuals showed only one DNA fragment of 659bp. Also, all three fragments(659, 493 and 166bp) were showed in heterozygous(Nn) carrier animals. The proportions of normal, carrier and PSS pigs within crossbred population of pigs were 81%, 15% and 4%, respectively. According to the results of analysis of variance for the association of genotypes of RYR1 of pigs at 30kg, day age at 90kg and average daily gains, the RYR1 nn genotype was very higher than RYR1 NN genotype for day age at 30kg with 5% level of significant difference, but no significant difference for association of any other genotypes with day age at 90kg and average daily gain in crossbred pigs. Therefore, DNA diagnosis by using PCR-RFLP analysis for the PSS gene was useful for large-scale screening of commercial pigs in the swine industry.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.3
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• pp.398-404
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• 2015

The first aim of the study was to compare selected meat quality parameters in porkers without the gene $RYR1^T$ (ryanodine receptor gene). These were porkers slaughtered at 100 to 115 kg and 116 to 130 kg live weight. The second aim of the study was to determine the occurrence frequency of standard-quality meat (red, firm, nonexudative [RFN]) and the occurence frequency of defective meat (pale, soft, exudative [PSE] and acid, soft, exudative [ASE]). The analysis was conducted on the longissimus lumborum muscle in 114 crossbred porkers. The porkers were a cross of Camborough 22 sows and boars from lines 337PIC (Pig Improvement Company), Norsvin Landrace and Pietrain. All of the animals were provided with identical environmental and nutritional conditions. The average weight of the slaughtered animals in the light and heavy groups was 110 kg and 122 kg, respectively. Both groups had the same average post-slaughter meatiness (56.5%). A statistical analysis of selected meat-quality parameters did not show any significant differences between the weight groups. On the other hand, the classification based on carcass quality showed an occurence frequency of defective meat in heavier crossbred porkers (116 to 130 kg) that was three times higher than in those cross bred animals which weighed 100 to 115 kg when slaughtered. In porkers without the gene $RYR1^T$, the defective meat types PSE and ASE occurred with a frequency of 17.54%.

• Reproductive and Developmental Biology
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• v.28 no.1
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• pp.37-43
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• 2004

This study was carried out to investigate PSS (Porcine Stress Syndrome) with the PSE (Pale, Soft, Exudative) in 319 different pigs(Yorkshire 150; Landrace 89 and Duroc 80). The PCR-RFLP method was adapted to detect the ryanodine receptor (RYR 1) gene mutation and to estimate the genotype frequency of the RYR1 gene in breeding pig population. The DNA samples were collected from hair follicles of pigs of Yorkshire, Landrace and Duroc. After DNA amplification by PCR, the PCR products were digested by restriction enzyme, Cfo I. Primary PCR products of ryanodine receptor gene were length of 659 bp in hair follicle and their second PCR products were length of 522 bp in hair follicle. The exon region (522 bp) including point mutation ($C \arrow T; Arg \arrow Cys$) in the porcine ryanodine receptor gene, which is a causal mutation for PSS, was digested with Cfo I restriction enzyme. The RYR1 gene was classifed into three genotypes by agarose gel electrophoresis. The normal homozygous (NN) individuals showed two DNA fragments consisted of 439 and 83 bp. The mutant homozygous (nn) individuals showed only one DNA fragment 522 bp. In addition, all three fragments (522, 439 and 83 bp) were showed in heterozygous (Nn) carrier animals. The normal homozygous (NN), heterozygous (Nn) and mutant homozygous (nn) were 98.00, 2.00 and 0.00% in Yorkshire pigs, 87.64, 11.24 and 1.12% in Landrace, 100.00, 0.00 and 0.00% in Duroc, respectively. The gene frequencies of N and n were 0.990 and 0.010 in Yorkshire pigs, 0.933 and 0.067 in Landrace, 1.000 and 0.000 in Duroc, respectively.

• Food Science of Animal Resources
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• v.24 no.4
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• pp.349-354
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• 2004

Stress-susceptible pigs have been known as the porcine stress syndrome (PSS), swine PSS, also known as malignant hyperthermia (MH), is characterized as sudden death and production of poor meat quality such as PSE (pale, soft and exudative) meat after slaughtering. PSS and PSE meat cause major economic losses in the pig industry. A point mutation in the gene coding for the ryanodine receptor (RYR1) in porcine skeletal muscle, also known calcium (Ca$^{2+}$) release channel, has been associated with swine PSS and halothane sensitivity. We used the PCR-RFLP(restriction fragment length polymorphism) and PCR-SSCP (single strand conformation polymorphism) methods to detect the PSS gene mutation (C1843T) in the RYR1 gene and to estimate genotype frequencies of PSS gene in Korean pig breed populations. In PCR-RFLP and SSCP analyses, three genotypes of homozygous normal (N/M), heterozygous carrier (N/n) and homozygous recessive mutant (n/n) were detected using agarose or polyacrylamide gel electrophoresis, respectively. The proportions of normal, carrier and PSS pigs were 57.1, 35.7 and 7.1％ for Landrace, 82.5, 15.8 and 1.7％ far L. Yorkshire, 95.2, 4.8 and 0.0％ for Duroc and 72.0, 22.7 and 5.3％ for Crossbreed. Consequently, DNA-based diagnosis for the identification of stress-susceptible pigs of PSS and pigs producing PSE meat is a powerful technique. Especially, PCR-SSCP method may be useful as a rapid, sensitive and inexpensive test for the large-scale screening of PSS genotypes and pigs with PSE meat in the pork industry.y.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.2
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• pp.280-285
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• 2006

The current study was conducted to investigate the relationship between stress related gene and meat quality in pigs. A total number of 212 three-way cross bred (Landrace-$Yorkshire{\times}Duroc$) and 38 Duroc were sampled from the Korean pig industry to determine genotype frequency of porcine stress syndrome (PSS) and heat shock protein 70 kDa (HSP70) genes and their relationship with carcass traits and longissimus meat quality. Screen of HSP70 was performed by the single strand conformation polymorphism (SSCP) technique. Based on the analysis of restriction fragment length polymorphism (RFLP) in ryanodine receptor 1 (RYR1) gene, genetic disorder of PSS was related to a mutation at $18,168^{th}$ (C to T) of exon 17. There was no significant difference in ultimate meat pH and backfat thickness between HSP70 K1-AA type and -BB type in pure Duroc breed. In Landrace-$Yorkshire{\times}Duroc$ (L-$Y{\times}D$) cross bred pig, our results indicated that HSP70 derivate type in Duroc had a limited effect on backfat thickness, but L-$Y{\times}D$ type had a noticeable linkage with HSP70 K1-AA and K3-AB. This tendency was also observed in hot carcass weight where HSP70 K1-AA and K3-AB resulted in heavier weight with 86.3 kg compared to HSP70 K1-AB and K3-BB of 74.3 kg. Results imply that stress related HSP70 genotype has a potential association with backfat thickness and carcass weight.

• Journal of Animal Science and Technology
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• v.45 no.5
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• pp.841-846
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• 2003

Landrace(L), Largewhite(Lw), Korean Native Pig(KNP) and commercial hybrid were experimented to determine holothane sensitivity, RYR gene mutation and quality profiles. In the results of halothane test, the incidence of halothane positive pigs was similar between L and Lw. But, the rate of dubious halothane positive type was higher in L than Lw. In hal-gene analysis, halothane-positive pigs(nn) were not found in any tested breed and heterotype(Nn) appeared only in one pig of L. Of the breed effect on the quality profiles, there were no differences in pH$_1$(pH at 1hr postslaughter), but pH$_{u}$(pH at 24hr postslaughter) was significantly higher in commercial hybrid and KNP than other breeds(p〈0.05). Color assessed by National Pork Producers Council(NPPC) and CIE L$^{*}$ was significantly paler in L breed than other breeds(p〈0.05). Significant differences were found in water holding capacity(WHC) and cooking loss in KNP(p〈0.05).