Tozaki Teruaki, Sato Fumio, Hill Emmeline W, Miyake Takeshi, Endo Yoshiro, Kakoi Hironaga, Gawahara Hitoshi, Hirota Kei-ichi, Nakano Yasuko, Nambo Yasuo, Kurosawa Masahiko
Department of Molecular Genetics, Laboratory of Racing Chemistry, Utsunomiya, Tochigi 320–0851, Japan.
J Vet Med Sci. 2011 Dec;73(12):1617-24. doi: 10.1292/jvms.11-0295. Epub 2011 Aug 11.
Myostatin is a member of the transforming growth factor-β family with a key role in inhibition of muscle growth by negative regulation of both myoblast proliferation and differentiation. Recently, a genomic region on ECA18, which includes the MSTN gene, was identified as a candidate region influencing racing performance in Thoroughbreds. In this study, four SNPs on ECA18, g.65809482T>C, g.65868604G>T, g.66493737C>T, and g.66539967A>G, were genotyped in 91 Thoroughbred horses-in-training to evaluate the association between genotype and body composition traits, including body weight, withers height, chest circumference, cannon circumference, and body weight/withers height. Of these, statistically differences in body weight and body weight/withers height were associated with specific genotypes in males. Specifically, body weight/withers height showed statistically significant differences depending on genotype at g.658604G>T, g.66493737C>T, and g.66539967A>G (P<0.01) in males during the training period. Animals with a genotype associated with suitability for short-distance racing, C/C at g.66493737C>T, had the highest value (3.17 ± 0.05 kg·cm(-1)) for body weight/withers height in March, while those with a genotype associated with suitability for long-distance racing, T/T, had the lowest (2.99 ± 0.03 kg·cm(-1)). In females, the trends in the association of body weight/withers height with genotypes were similar to those observed in males. As the SNPs are not believed to be linked to coding variants in MSTN, these results suggest that regulation of MSTN gene expression influences skeletal muscle mass and hence racing performance, particularly optimum race distance, in Thoroughbred horses.
肌肉生长抑制素是转化生长因子-β家族的成员，通过对成肌细胞增殖和分化的负调控，在抑制肌肉生长中起关键作用。最近，位于18号马染色体（ECA18）上的一个基因组区域（包括MSTN基因）被确定为影响纯种马比赛成绩的候选区域。在本研究中，对91匹正在训练的纯种马的ECA18上的4个单核苷酸多态性（SNP），即g.65809482T>C、g.65868604G>T、g.66493737C>T和g.66539967A>G进行基因分型，以评估基因型与包括体重、肩高、胸围、管围和体重/肩高在内的身体组成性状之间的关联。其中，体重和体重/肩高的统计学差异与雄性马的特定基因型有关。具体而言，在训练期间，雄性马的体重/肩高在g.658604G>T、g.66493737C>T和g.66539967A>G位点上，根据基因型显示出统计学上的显著差异（P<0.01）。在3月份，g.66493737C>T位点上与短距离比赛适宜性相关的基因型C/C的动物，其体重/肩高值最高（3.17±0.05kg·cm⁻¹），而与长距离比赛适宜性相关的基因型T/T的动物，其体重/肩高值最低（2.99±0.03kg·cm⁻¹）。在雌性马中，体重/肩高与基因型的关联趋势与雄性马中观察到的相似。由于这些SNP被认为与MSTN中的编码变异无关，这些结果表明，MSTN基因表达的调控影响骨骼肌质量，从而影响纯种马的比赛成绩，特别是最佳比赛距离。
