RESUMO
Thyroid hormones play an important role in regulating metabolism and can affect metabolism-related traits such as fat deposition. The thyroglobulin (TG) gene produces the precursor of thyroid hormones and has been proposed as a candidate gene for a quantitative trait locus with an effect on fat deposition. In this study, we identified 4 novel single nucleotide polymorphisms (SNPs) in the 5' flanking region of the TG gene using a DNA sequencing method. The SNP marker association analysis indicated that the T1355C SNPs were significantly associated with meat percentage (P < 0.05). A significant association between the G1356A polymorphism and live weight and loin muscle area was also detected (P < 0.05). However, no significant association was found between 4 SNPs and the other growth, carcass composition, and meat quality traits including intramuscular fat. The results of this study suggest that TG gene-specific SNPs may be a useful marker for growth traits in marker-assisted selection programs in beef cattle.
Assuntos
Estudos de Associação Genética , Polimorfismo de Nucleotídeo Único/genética , Locos de Características Quantitativas/genética , Tireoglobulina/genética , Animais , Composição Corporal/genética , Peso Corporal/genética , Bovinos , China , Genótipo , Carne VermelhaRESUMO
Myogenic determination factor 1 (MyoD1) and myogenic factor 6 (Myf6) genes belong to the myogenic differentiation (MyoD) gene family, which play key roles in growth and muscle development. The study aimed to investigate the effects of variants in cattle MyoD1 and Myf6 on carcass and meat traits. We screened single nucleotide polymorphisms (SNPs) of both genes in 8 cattle populations, including Simmental, Angus, Hereford, Charolais, Limousin, Qinchuan, Luxi, and Jinnan by sequencing. The G782A locus was identified in exon 1 of MyoD1 (MyoD1-BglI) as well as the T186C locus in exon 1 of Myf6 (Myf6-ApaLI). For the two SNPs, the A allele was significantly more frequent than the B allele in the populations tested. The χ(2) test showed that the MyoD1-BglI locus conformed to Hardy-Weinberg equilibrium in the 8 populations, as did the Myf6-ApaLI locus, with the exception of the Simmental population (P > 0.05). Association analysis revealed that the MyoD1-BglI locus was significantly associated with loin muscle area (LMA) (P < 0.05), and the Myf6-ApaLI locus was significantly associated with carcass length (CL) (P < 0.05). Animals with BB and AB genotypes for the MyoD1-BglI locus had larger LMAs compared to animals with AA genotype. Individuals with BB genotype had longer CLs compared to those with AA and AB genotypes. We conclude that the two SNPs might provide useful genetic markers, opening up new possibilities for cattle breeding and improvements in gene-assisted selection.