Molecular characterization, expression profile and polymorphisms of the porcine TNNC2 gene
Molecular characterization, expression profile and polymorphisms of the porcine TNNC2 gene
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猪TNNC2基因的分子特征、表达谱和多态性
DOI：
10.1111/j.1601-5223.2008.02083.x
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发表时间：
2008-12-01
期刊：
影响因子：
2.7
通讯作者：
Zhong, Wanfu
中科院分区：
文献类型：
--
作者：
Li, Yanfang;Chen, Yaosheng;Zhong, Wanfu
快速骨骼肌钙蛋白C （Fast skeletal troponin C, TNNC2）在肌肉收缩调控中起关键作用，并调节肌肉纤维的Ca2+活化特性。本研究鉴定了猪TNNC2基因的全长cDNA，该基因由一个65 bp的5'UTR、一个483 bp的ORF和一个174 bp的3' UTR组成。Northern blot分析表明，TNNC2基因有一个约0.7 kb的转录本，仅在骨骼肌（肱三头肌、股二头肌和背最长肌）中表达。SDS-PAGE和Western blotting分析表明，猪TNNC2蛋白由160个氨基酸组成，分子量为18 kDa。猪TNNC2基因全长3.2 kb，由6个外显子组成。所有外显子/内含子边界均符合GT/AG规则。在杜洛克猪、长白猪、兰塘猪和大花白猪中共发现了20个TNNC2基因多态性，包括3个错义突变和17个内含子替换。采用PCR-RFLP方法对5个多态性进行了分型，分别在兰塘猪、大花白猪、长白猪、大白猪和杜洛克猪中进行了分型。中国本土品种（兰塘和大花白）与西方品种（长白、大白和杜洛克）的基因型频率存在显著差异。这些数据表明，TNNC2基因是研究猪骨骼肌发育调控基因表达的良好模型系统，也是研究候选基因与猪骨骼肌生长性状相关性的新标记。
Fast skeletal troponin C (TNNC2) plays a key role in the regulation of muscle contraction, and modulates the Ca2+-activation characteristics of muscle fibers. In this study, we characterized the full-length cDNA of the porcine TNNC2 gene, which is composed of a 65 bp 5'UTR, a 483 bp (ORF) and a 174 bp 3' UTR. Northern blot analysis indicated that the TNNC2 gene had one transcript of approximately 0.7 kb and was expressed exclusively in skeletal muscle (triceps brachii, biceps femoris and longissimus dorsi). SDS-PAGE and Western blotting analysis indicated that the porcine TNNC2 protein comprised 160 amino acids, and had a molecular mass of 18 kDa. The porcine TNNC2 gene, which spans 3.2 kb, was isolated and was found to be composed of six exons. All exon/intron boundaries adhered to the GT/AG rule. Altogether 20 nucleotide polymorphisms of the TNNC2 gene were discovered in Duroc, Landrace, Lantang and Dahuabai pigs, and included three missense mutations and 17 intronic substitutions. Five of the polymorphisms were genotyped in Lantang, Dahuabai, Landrace, Large White and Duroc pigs using PCR-RFLP. Significant differences in genotype frequencies were observed between the Chinese native breeds (Lantang and Dahuabai) and the western breeds (Landrace, Large White and Duroc). These datas have identified the TNNC2 gene as an excellent model system for studies of developmentally regulated gene expression and a novel marker suitable for studies of the association of candidate genes with growth traits in porcine skeletal muscle.