RESUMO
Body measurement and meat quality traits play important roles in the evaluation of productivity and economy in cattle, which are influenced by genes and environmental factors. PRKAG2, which encodes the γ2 regulatory subunit of AMPK, is associated with key metabolic pathways in muscle. We detected bovine PRKAG2 gene polymorphisms and analyzed their associations with body measurement and meat quality traits of cattle. DNA samples were taken from 578 Qinchuan cattle aged 18-24 months. DNA sequencing, polymerase chain reaction-restriction fragment length polymorphism, and time-of-flight mass spectrometry were used to detect PRKAG2 single nucleotide polymorphisms (SNPs). Sequence analysis revealed three SNPs in exon 3 (g.95925G>A, g.95973G>C, and g.95992A>G) and one g.96058T>C mutation in intron 3. g.95973G>C, g.95992A>G, and g.96058T>C each showed 3 genotypes: GG, GC, and CC; AA, AG, and GG; and TT, TC, and CC, respectively. In contrast, g.95925G>A only showed 2 genotypes, GG and GA. Analysis showed that g.95925G>A had no effects on body measurement and meat quality traits, whereas the other 3 polymorphisms were significantly associated with some of the body measurement and meat quality traits in the Qinchuan cattle population. It is inferred that the PRKAG2 gene can be used for marker-assisted selection to improve the body measurement and meat quality traits in the Qinchuan cattle population.
Assuntos
Proteínas Quinases Ativadas por AMP/genética , Qualidade dos Alimentos , Carne/normas , Animais , Sequência de Bases , Tamanho Corporal , Bovinos , Frequência do Gene , Estudos de Associação Genética , Polimorfismo de Fragmento de Restrição , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNARESUMO
The aim of this study is to use Y-chromosome gene polymorphism method to investigate regional differences in genetic variation and population evolution history of the Chinese native cattle breeds. Six Y-chromosome short tandem repeat (Y-STR) loci (UMN0929, UMN0108, UMN0920, INRA124, UMN2404, and UMN0103) were analyzed using 1016 healthy and heterogenetic males and 90 females of 9 native cattle breeds (Qinchuan, Jinnan, Zaosheng, Luxi, Nanyang, Jiaxian, Dabieshan, Yanbian, and Menggu) in China. Allele frequency and gene diversity were calculated for the various populations. The results indicated that Y-STRs in the 6 loci have polymorphisms and genetic diversity in Chinese cattle populations. The genetic diversity analysis revealed that the Chinese cattle populations have a close genetic relationship. The analysis of INRA124, UMN2404, and UMN0103 loci revealed the original history of Chinese cattle because of which cattle belonging to Bos taurus or Bos indicus could be determined. Interestingly, a declining zebu introgression was displayed from South to North and from East to West in the Chinese geographical distribution, which implied that cattle population from various regions of China had been subjected to somewhat different evolutionary history. This conclusion supported other evidences such as earlier archaeological, historical research, and blood protein polymorphism analysis.
Assuntos
Cruzamento , Bovinos/genética , Variação Genética , Repetições de Microssatélites/genética , Cromossomo Y/genética , Animais , China , Feminino , Frequência do Gene , Geografia , Haplótipos , Masculino , FilogeniaRESUMO
The peroxisome proliferator-activated receptor gamma (PPAR-γ) is a key molecule in adipocyte differentitation; it transactivates multiple target genes in lipid metabolic pathways. Using PCR-SSCP and DNA sequencing, we evaluated a potential association of an SNP (72472 G﹥T in exon7) of the bovine PPAR-γ gene with carcass and meat quality traits in 660 individuals from five Chinese indigenous cattle breeds, Qinchuan (QC), Luxi (LX), Nanyang (NY), Jiaxian (JX), and Xianan (XN). This 72472 G﹥T mutation identified a missense mutation, Q448H. Two alleles were named C and D. Allele frequencies of PPAR-γ-C/D in the five breeds were 0.7815/0.2185, 0.9/0.1, 0.7442/0.2558, 0.7051/0.2949, and 0.8333/0.1667 for QC, NY, JX, LX, and XN, respectively. Except for the XN breed, all breeds were in Hardy-Weinberg equilibrium at this locus. The polymorphism information content was low for NY and XN (0.16 and 0.24, respectively), while it was moderately high for QC, JX, and LX (0.28, 0.31 and 0.33, respectively). Correlation analysis showed significant association of this missense mutation with carcass length, backfat thickness and water holding capacity in the QC breed. Animals with the genotype CD had significantly greater carcass length than those with genotypes CC and DD, while animals with genotype CC had significantly greater backfat thickness than those with genotypes CD and DD. Animals with genotype CC had lower water holding capacity than those with the genotypes CD and DD. In conclusion, this locus is a candidate for a major quantitative trait locus affecting production traits and could be used for beef breeding selection.
Assuntos
Cruzamento , Bovinos/genética , Estudos de Associação Genética , Carne/normas , Mutação de Sentido Incorreto/genética , PPAR gama/genética , Característica Quantitativa Herdável , Sequência de Aminoácidos , Animais , Sequência de Bases , China , Éxons/genética , Frequência do Gene/genética , Loci Gênicos/genética , Genótipo , Dados de Sequência Molecular , PPAR gama/química , Reação em Cadeia da Polimerase , Polimorfismo Conformacional de Fita Simples/genética , Análise de Sequência de DNARESUMO
Qinchuan is a red or yellow draft and beef breed in China. In order to identify a predictor of carcass traits on the basis of associations between carcass traits and gene polymorphism, variation in the bovine chemerin gene was investigated using PCR-single-strand conformational polymorphism and DNA sequencing. An SNP of A868G located in exon 2 of the Bos taurus chemerin gene was detected in 716 samples of six breeds (Jiaxian red, Luxi, Nan yang, Qinchuan, Simmental and Luxi crossbred steers, and Xia'nan), all in China, and three genotypes (AA, AG and GG) were found. Based on the χ(2) test, the AA/AG/GG genotype frequencies of all six breeds were found to be in Hardy-Weinberg equilibrium. A possible association of A868G with some carcass traits was investigated in 106 Qinchuan cattle. Animals with the AG genotype were found to have significantly lower mean loin eye area and meat tenderness compared to those with the AA and GG genotypes. However, there was no significant association between any individual haplotype and backfat thickness, water holding capacity or marbling score. We suggest that A868G could be used as a molecular marker in marker-assisted selection for carcass traits.