Key Laboratory of Swine Genetics and Breeding, Ministry of Agriculture & Key Laboratory of Agricultural Animal Genetics and Breeding, Ministry of Education, College of Animal Science and Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, P. R. China.
J Appl Genet. 2010;51(1):51-7. doi: 10.1007/BF03195710.
The contractile protein troponin I (TnI), a constituent protein of the troponin complex located on the thin filaments of striated muscle, is involved in inhibition of calcium-induced myosin ATPase activity (and thus contraction). TnI-slow (slow-twitch skeletal muscle isoform, named TNNI1) and TnI-fast (fast-twitch skeletal muscle isoform, named TNNI2) are muscle-fiber-type-specific proteins, and expression of their genes may affect the composition of muscle fiber, thereby influencing the meat quality traits. Thus, the TnI genes are potential candidate genes for traits related to meat quality in animals. Association of 2 SNPs (EU743939:g.5174T>C in intron 4, and EU743939:g.8350C>A in intron 7) of the TNNI1 gene and a SNP (EU696779:g.1167C>T in intron 3) of the TNNI2 gene with 11 meat quality traits were studied on 334 Large White x Meishan F(2) pigs. In the TNNI1 gene, g.5174T>C and g.8350C>A were found to be significantly associated with intramuscular fat content and meat color value of biceps femoris. The g.5174T>C also showed significant effects on meat color value and marbling score of longissimus dorsi, as well as pH of longissimus dorsi and semispinalis capitis. The g.1167C>T polymorphism in the TNNI2 gene affected significantly the pH of longissimus dorsi, meat color value of longissimus dorsi and semispinalis capitis, marbling score of longissimus dorsi, and intramuscular fat.
肌钙蛋白 I（TnI）是一种收缩蛋白，是位于横纹肌细肌丝上的肌钙蛋白复合物的组成蛋白，参与抑制钙诱导肌球蛋白 ATP 酶活性（从而抑制收缩）。TnI-慢（慢肌骨骼肌同工型，命名为 TNNI1）和 TnI-快（快肌骨骼肌同工型，命名为 TNNI2）是肌肉纤维类型特异性蛋白，其基因的表达可能影响肌肉纤维的组成，从而影响肉质性状。因此，TnI 基因是与动物肉质性状相关的潜在候选基因。在 334 头大白猪×梅山猪 F2 代猪中，研究了 TNNI1 基因的 2 个 SNP（EU743939：g.5174T>C 位于内含子 4，EU743939：g.8350C>A 位于内含子 7）和 TNNI2 基因的 1 个 SNP（EU696779：g.1167C>T 位于内含子 3）与 11 个肉质性状的关联。在 TNNI1 基因中，g.5174T>C 和 g.8350C>A 与股二头肌肌内脂肪含量和肉色值显著相关。g.5174T>C 还对背最长肌肉色值和大理石纹评分以及背最长肌和半棘肌 pH 值有显著影响。TNNI2 基因中的 g.1167C>T 多态性显著影响背最长肌 pH 值、背最长肌和半棘肌肉色值、背最长肌大理石纹评分和肌内脂肪含量。
