title: Sequence variants at the myostatin gene locus influence the body composition of Thoroughbred horses.
abstract: 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.
authors.affiliation: Department of Molecular Genetics, Laboratory of Racing Chemistry, Utsunomiya, Tochigi 320–0851, Japan. ttozaki@lrc.or.jp
authors.forename: Teruaki
authors.initials: T
authors.lastname: Tozaki
authors.forename: Fumio
authors.initials: F
authors.lastname: Sato
authors.forename: Emmeline W
authors.initials: EW
authors.lastname: Hill
authors.forename: Takeshi
authors.initials: T
authors.lastname: Miyake
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Endo
authors.forename: Hironaga
authors.initials: H
authors.lastname: Kakoi
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Gawahara
authors.forename: Kei-ichi
authors.initials: K
authors.lastname: Hirota
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Nakano
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Nambo
authors.forename: Masahiko
authors.initials: M
authors.lastname: Kurosawa
mesh_terms: D000818:Animals; D001823:Body Composition / Q000235:genetics* / Q000502:physiology; D005260:Female; D005838:Genotype; D006736:Horses / Q000235:genetics* / Q000502:physiology; D008297:Male; D055435:Myostatin / Q000235:genetics / Q000378:metabolism*; D010805:Physical Conditioning, Animal; D020641:Polymorphism, Single Nucleotide
chemical_list: D055435:Myostatin