Association of SNP marker in the thyroglobulin gene with carcass and meat quality traits in Korean cattle.

摘要

Thyroid hormones play an important role in regulating metabolism and can affect homeostasis of fat depots. The gene encoding thyroglobulin (TG), producing the precursor for thyroid hormones, has been proposed as a positional and functional candidate gene for a QTL with an effect on fat deposition. The single nucleotide polymorphism (SNP) occurs in the 5' promoter region of the TG gene and is widely used in marker assisted selection (MAS) programmes to improve the predictability of marbling level and eating quality in beef cattle. This study identified 3 SNP at the 5' promoter region of the TG gene in Korean cattle. Of these C257T and A335G were previously unreported, new SNP. The sequence data were submitted to GenBank (GenBank accession number: AY615525). The previously reported C422T SNP showed 3 genotypes, CC, CT and TT, by digestion with the restriction enzyme MflI using the PCR-RFLP method. A new allelic variant corresponding to the C rightwards-arrow T and A rightwards-arrow G mutations at positions 257 and 335, respectively, could be detected by single stranded conformation polymorphism (SSCP) analysis. Gene-specific SNP marker association analysis indicated that the C422T SNP marker was significantly associated (P < 0.05) with marbling score. Animals with the CC and CT genotypes had higher marbling score than those with the TT genotype. Results from this study suggest that TG gene-specific SNP may be a useful marker for meat quality traits in future MAS programs in Korean cattle.