• Journal of Animal Science and Technology
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• v.54 no.1
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• pp.1-8
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• 2012

This study aimed to investigate the single nucleotide polymorphisms (SNPs) of the porcine MC4R gene and validate the effect of the MC4R genotype for marker assisted selection (MAS). Six amplicons were produced to analyze the entire base sequences of the porcine MC4R gene and six SNPs were detected (c.-780C>G, c.-135C>T, c.175C>T-Leu59Leu, c.707A>G-Arg236His, c.892A>G-Asp298Asn, and c.*430A>T). Linkage disequilibrium (LD) of the six SNPs was analyzed by performing haploid analysis. There was a perfect linkage disequilibrium in c.-780C>G, c.-135C>T, c.175C>T-Leu59Leu, c.707A>G-Arg236His, and c.*430A>T. Only the c.892A>G (Asp298Asn) SNP showed a very low LD with an $r^2$ value of 0.028 and the D' value of 0.348. As a result, the two SNPs-c.707A>G (Arg236His) and c.892A>G (Asp298Asn)-were selected to extract the genotype frequencies from the 5 pig breeds by using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) genotype analysis method. The SNP frequency of c.707A>G (Arg236His) indicated the presence of the A (His) allele only in Yorkshire, while the G allele was fixed in the KNP, Landrace, Berkshire, and Duroc. Association analysis was carried out in 484 pigs with the c.707A>G (Arg236His) SNP and the meat quality traits of four different pig cross populations: a significant association was noted in crude fat, sirloin moisture, meat color, and the degree of red and yellow coloration. The frequency of the c.892A>G(Asp298Asn) SNP genotype varied among the breeds; while Duroc showed the highest frequency of the A (Asn) allele, KNP showed the highest frequency of the G (Asp) allele. Association analysis was carried out in 1126 pigs with the c.892A>G (Asp298Asn) SNP and the meat quality traits of four pig populations: a highly significant linkage was noted in the back-fat thickness (P<0.002). It was found that the back-fat thickness was higher in individuals with the AA genotype than in those with the AG or GG genotype. Thus, in this study, we verified that the c.892A>G (Asp298Asn) SNP in the pig MC4R gene has a sufficient effect as a gene marker for MAS in Korean pork industry.

• Journal of Animal Science and Technology
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• v.53 no.2
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• pp.107-111
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• 2011

This study was undertaken to reveal the relationship between genetic variations and the basic coat color classification system in Jeju horses. Genetic variations of the melanocortinreceptor 1 (MC1R) and agouti signaling protein (ASIP) genes were investigated using pyrosequencing technique. A nucleotide substitution mutation for MC1R g.901C>T and an ASIP 11-bp deletion mutation were screened. Black horses had MC1R $E^+$/- ($E^+/E^+$ or $E^+/E^e$) and ASIP $A^a/A^a$ genotypes. In contrast, chestnut horse genotypes were MC1R $E^e/E^e$ and ASIP -/-. Thus, black and bay horses have at least one dominant MC1R allele, $E^+$, whereas chestnut horses have homozygous recessive alleles $E^e/E^e$. This suggests that the MC1R genotypes determine chestnut or black/bay coat color, regardless of the genotype distribution of ASIP. In addition, the horses with MC1R $E^+$/- and a dominant ASIP $A^A$/- allele showed bay coat color, but not black, suggesting that the ASIP $A^A$ allele represses black coat color development in the hairs of the body, but not in the mane and all four legs. Pedigree analysis showed a consistent relationship between the genotype distribution of the MC1R and ASIP genes and basic coat color patterns, even in the $F_1$ progeny. The results of this study revealed the relationship between the coat color phenotype and genetic background and suggested that useful information may be provided for molecular breeding of Jeju horses.

• Journal of Life Science
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• v.19 no.3
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• pp.384-389
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• 2009

This study was carried out to elucidate the relation between expression levels of three melanin synthesis genes (Tyrosinase, Tyrosinase-related protein 1 and Dopachrome tautomerase) according to the Melanocortin-1 receptor genotypes with coat color patterns in Hanwoo cattle, Jeju black cattle and Holsteins. Using real-time semiquantitative reverse transcription-PCR assay (RT-PCR), the expression levels of these three genes were analyzed in skin tissues from four representative coat colored areas: yellowish-brown from MC1R e/e Hanwoo, wild type black from $E^+/E^+$ Jeju black cattle (JBC), and dominant black and white pied regions from $E^D/E^D$ Holstein. The TYR, TYRP1 and DCT genes showed higher expression levels of 4.5, 2.3 and 2.5 times higher in the black skin area of Holsteins than those of from JBC, respectively (p<0.001). In addition, the expression levels of these three genes from JBC were significantly higher than those from Hanwoo cattle (p<0.001). These results show that coat color phenotypes in Hanwoo cattle, JBC and Holsteins is directly correlated with TRY, TYRP1 and DCT transcription levels, which probably reflected involvement with MC1R genotypes; e/e in Hanwoo, $E^+/E^+$ in JBC and $E^D/E^D$ in Holsteins. Consequently, this study suggested that the status of MC1R protein may not only induce the transcription activities of a series of TYR and its related genes responsible for melanin synthesis, but also determine the levels of total melanin contents in bovine skin.

• Journal of Animal Science and Technology
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• v.54 no.4
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• pp.255-265
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• 2012

The objectives of this study were to investigate MC1R genotype, coat color, and muzzle phenotype variationsin the Korean native brindle cattle (KNBC) maintaining family lines and to establish the mating system for increased brindle coat color appearance. KNBC with genotype and phenotype records were selected as experimental animals. The relationship between melanocortin 1 receptor (MC1R) genotypes, verified by PCR-RFLP, and brindle coat color appearance was determined. Fragments of the MC1R gene amplified by PCR were digested with MspI and RFLP was determined. KNBC had $E^+E^+$, $E^+e$, and ee genotypes. The $E^+e$ genotype was most common with 65%, compared to $E^+E^+$ (33.33%), or ee (1.67%). When the sire had $E^+e$ genotype and the dam had $E^+E^+$ genotype, and both of them had the whole body-brindle coat color, all of their offspring (4/4) had whole body-brindle coat color. When the sire had $E^+E^+$ genotype and the dam had $E^+e$ genotype, and both had whole body-brindle coat color, 44.44% (4/9) of the offspring had whole body-brindle coat color. The mating between the sires and dams with these two genotypes with whole body-brindle coat color may have the highest whole body-brindle coat color appearance in their offspring. Muzzle grades 3 or 4 were more common than other muzzle grades. This is the first report indicating the segregation of MC1R genotypes and the inheritance of coat color through family lines in KNBC. The mating system proposed from this study may increase the possibility of brindle coat color appearance in KNBC.

• Journal of the Korean Chemical Society
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• v.53 no.6
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• pp.742-748
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• 2009

In the meat industry, correct breed information in food labeling is required to assure meat quality. Genetic markers provide corroborating evidence to identify breed. We described the development of DNA markers to discriminate between Korean beef cattle (Hanwoo), Holstein, and mixed cow beefs. As most breeds are standardized for coat colour, the melanocortin 1 receptor (MC1R) gene, involved in the regulation of eu/pheomelanins synthesis, has been suggested as marker for breed traceability of products of animal origin. We also designed sex-determining region Y (SRY) gene specific primers for Y chromosome detection. In this study, fragments of MC1R gene and SRY gene were amplified by multiplex-PCR and subjected to digestion by MspA1I restriction endonuclease. Reaction products were analysised by denaturing high performance liquid chromatography (DHPLC). As a result, we identified 6 DHPLC peak types from MC1R gene and SRY gene analysis. DHPLC method showed more sensitive than RFLP method for DNA fragments analysis. Therefore, DHPLC method can apply to identify for Hanwoo, Holstein and mixed beef.

• Korean Journal of Poultry Science
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• v.41 no.1
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• pp.7-14
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• 2014

Tyrosinase (TYR) gene is located on chromosome 1 in chicken and it is composed of five exons and four introns. TYR gene is described as a key enzyme in melanin biosynthesis. Most examples of complete albinism in chicken have been due to defects in the tyrosinase gene. The association of feather color and sequence polymorphism in the Tyrosinase (TYR) gene was investigated using Korean Native chicken H breed (H_PL), Korean Native chicken L/W breed(L/W_PL) and 'Woorimatdag' commercial chickens (Woorimatdag_CC). From L_PL and W_PL breed analyses, 4 synonymous SNPs (locus G33A, G116A, C217T and C247T) and 2 SNPs (G838A and G958A) were detected in 4th exon and 4th intron of TYR gene respectively. The genotype frequencies for 6 SNPs were compared between L_PL and W_PL and W_PL represented homozygous SNP types in all the analyzed SNP positions while L_PL displayed various SNP types.