BTG1 (B-cell Translocation Gene 1) , a member of the BTG / TOB (Transducer of ErbB-2) family of anti-proliferation factors,has been proven to have an unfavorable effect on muscle fiber growth in several species. The porcine BTG1 gene was cloned and its 5' flanking promoter region sequence, and characterized the expression patterns in different tissues of adult pigs and in fetal skeletal muscle at different developmental stages in two breeds. The tissue distribution pattern analyses revealed that the mRNA of porcine BTG1 was ubiquitously expressed in the six tissues of both Landrace and Tongcheng pigs. Real-time quantitative reverse transcriptase-PCR results showed that BTG1 mRNA expression levels were significantly different among the three fetal ages in Tongcheng pigs,while no significant differences were found among the three ages in Landrace pigs. Furthermore,the expression of BTG1 in Landrace pigs was significantly lower than in Tongcheng pigs at all three ages. The temporal expression profiles of the BTG1 gene in mouse myoblast C 2 C 12 cells were shown to be consistent with those of the myogenin gene. A single nucleotide polymorphism (SNP) ,g. 281C > T,was identified in the 3'UTR and allele frequencies were detected in seven pig breed populations. Significant associations were found between the g. 281C > T polymorphism and growth and meat quality traits. Our results indicate that the porcine BTG1 gene could play a potential role in markerassisted selection and as such may be a gene of economic importance.
Zheng FengHe ShenZhiqiang DuMengjin ZhuBin FanM. F. RothschildShuhong ZhaoChangchun Li
Meat quality is an important trait in the pig industry.To identify genomic regions and haplotype blocks responsible for meat quality traits in pigs,a genome-wide association study was conducted for five traits including intramuscular fat content,pH at 45 min and 24 h,drip loss within 24 h and water-holding capacity in 231 Yorkshire barrows using illumina porcine 60k SNP chips.The results showed that a total of 344 single nucleotide polymorphisms(SNP)were significantly associated with five meat quality traits(P<1×10^(–4)).Moreover,323 SNPs were within the reported QTL regions,of which 21 were novel.Also,158 SNPs fell into the proximal region of meat quality related genes.In addition,25 haplotype blocks based on 116 SNPs were revealed with SNP combination patterns for five traits.Our study added new SNP information for identification of meat quality traits in pigs and will help elucidate the mechanisms of meat quality in pigs.
Qian DONGHuiying LIUXinyun LIWei WEIShuhong ZHAOJianhua CAO
Previous studies indicated that miR-29c is important for muscle development in mice and human,but its role in pigs is unknown.In this study,we detected the expression of miR-29c in Meishan longissimus lumborum(LL)muscle.The results showed that miR-29c was gradually upregulated during development of skeletal muscle in pig.Moreover,the expression of YY1 and Akt3 genes,which were confirmed to be targeted by miR-29c in mice,was decreased along with muscle development.Furthermore,the expression level of miR-29c was significantly higher in adult Meishan pigs than Large White pigs,while the expression of YY1 and Akt3 genes was significantly lower in Meishan pigs.These results indicated that the expression pattern of miR-29c was opposite to that of YY1 and Akt3 genes in pigs.Also,the luciferase assay indicated that miR-29s can target the YY1 gene in pigs.In addition,we identified a T to C mutation in the primary transcript of miR-29c,which was associated with the postmortem muscle pH in pigs.Based on these results,we concluded that miR-29c is also important in skeletal muscle development of pigs.
Weiya ZHANGWei WEIYuanyuan ZHAOShuhong ZHAOXinyun LI
