The melanocortin 1 receptor (MC1R) plays an important role in regulation of melanin pigment synthesis within mammalian melanocytes. Mutations within the gene encoding MC1R have been shown to explain coat color variations within several mammalian species including cattle. To develope a rapid and accurate method for the identification of Hanwoo meat, we performed a single nucleotide polymorphism (SNP) analysis in Melanocortin 1 receptor (MC1R) gene using TaqMan∨® MGB probe-based real-time PCR. Two specific probes (one for Hanwoo and the other for Holstein and Black angus) were designed.

GroE that is a heat shock protein composed of GroEL and GroES is known as an immunodominant target of both the humoral and cellular immune responses in bovine brucellosis. This study was carried out to characterize groE gene encoding heat shock proteins of B. abortus isolated in Korea and to evaluate the immunogenicity of the GroE protein expressed in E. coli system. In PCR the specific signals with the size of 2,077 bp were detected in five strains isolated from the mammary lymphnodes of the dairy cattle that were serologically positive and the reference strains.

Here I describe a multiplex allele specific PCR-based approach for the rapid detection between Hanwoo and Holstein meat associated with Melanocortin 1 receptor (MC1R) gene. Specific and universal oligonucleotide primers were used in combination to detect the presence of a single nucleotide polymorphism within the bovine MC1R DNA sequence. The presence of the bovine MC1R gene is indicated by the production of a single control PCR product, whilst positive samples generate an alternative smaller specific product over the same region. The mutations in MC1R104 codon revealed depending on the presence or absence of an indicative fragment amplified from the wild-type allele of this codon.

The meq gene was thought to be only detected in Marek's disease virus serotype 1 (MDV1) including a very virulent strain, Md5, while L-meq, in which a 180-bp sequence is inserted into the meq open reading frame, is found in other strains of MDV1, such as CVI988/R6. However, both meq and L-meq were previously detected by PCR in chickens infected with MDV1, suggesting hat MDV1 may consists of at least two subpopulations, one with meq, the other with L-meq. To further analyze these subpopulations, we analyzed the time course changes in distribution of these subpopulations among T cell subsets from chickens infected with MDV1. Both meq and L-meq were detected in CD4(+) and CD8(+) T cells infected with strain Md5 or CVI988/R6. The shift in MDV subpopulations from one displaying meq to the other displaying L-meq and/or the conversion from meq to L-meq occurred mainly in the CD8(+) T cell subset from Md5- infected chickens. PCR products corresponding to L-meq rather than meq were frequently amplified from the CD8(+) T cell subset from CVI988/R6-infected chickens. These results suggest that a dominant subpopulation of MDV1 changes depending on the T cell subsets, and that L-meq is dominantly present in the CD8(+) T cells which play a role in the clearance of pathogenic agents.