Analysis of HorseMyostatinGene and Identification of Single Nucleotide Polymorphisms in Breeds of Different Morphological Types

Abstract

Myostatin (MSTN) is a negative modulator of muscle mass. We characterized the horse (Equus caballus) MSTN gene and identified and analysed single nucleotide polymorphisms (SNPs) in breeds of different morphological types. Sequencing of coding, untranslated, intronic, and regulatory regions of MSTN gene in 12 horses from 10 breeds revealed seven SNPs: two in the promoter, four in intron 1, and one in intron 2. The SNPs of the promoter (GQ183900:g.26T>C and GQ183900:g.156T>C, the latter located within a conserved TATA-box like motif) were screened in 396 horses from 16 breeds. The g.26C and the g.156C alleles presented higher frequency in heavy (brachymorphic type) than in light breeds (dolichomorphic type such as Italian Trotter breed). The significant difference of allele frequencies for the SNPs at the promoter and analysis of molecular variance (AMOVA) on haplotypes indicates that these polymorphisms could be associated with variability of morphology traits in horse breeds.

The genetic origin and history of speed in the Thoroughbred racehorse

“…The presence of a 227-bp SINE insertion polymorphism (Ins227bp) located in the promoter region sequence may also be considered a putative functional variant and linkage disequilibrium between the two polymorphisms is high (r 2 = 0.73) but not complete 20 . The g.66493737C/T and Ins227bp variants are polymorphic in the Thoroughbred population; however, in a re-sequencing study that included populations of European horse breeds, the g.66493737C/T SNP was not polymorphic (minor allele frequency (MAF) < 0.05) and the Ins227bp allele was not identified 22 .…”

“…Recently, variation at the MSTN locus has been found to be highly predictive of genetic potential for race distance aptitude in Thoroughbred racehorses [18][19][20][21] and contributes to morphological type in other horse breeds 22 . The MSTN locus is associated with muscle hypertrophy phenotypes in a range of mammalian species [23][24][25][26][27] and a single nucleotide polymorphism (SNP, g.66493737C/T) located in the first intron of the MSTN gene influences speed in the Thoroughbred 19 .…”

Comparison of the Proximal Phalanx Parameters in Warmblood and Coldblood Horses with the Use of Peripheral Quantitative Computed Tomography

“…Before slaughter, or during visual inspection in the case of dead animals, morphological description was prepared based on the constitutional type of the horses. Each horse, according to its physical constitution, represented one of the following types: Warmblood horses (dolichomorphic type or light) and Coldblood horses (brachymorphic type or heavy) (4,14). Eleven Warmblood (W) horses, Polish Halfbred horses were represented by a warmblood breed crossed with thoroughbreds and used for sports purposes.…”

Brief Review of Equine Genomics: Prospects toward Exercise and Sports Science

“…12 Natural mutations of MSTN gene correlated to increased muscle mass were also identified in cattle, 38 sheep, 39 dogs, 40 fishes, 41 humans, 42 horses. 43 The very high muscle mass to body weight ratio observed in horses (55%), compared to other species, 3 is probably a trait targeted for artificial selection, especially in Thoroughbred horses. 32 Considering the important contribution of muscle power to flat race ability, the association between MSTN sequence variant and racing performance was investigated in a series of population-basis case control study by separating thoroughbreds (n=148) on the basis of retrospective racecourse performance.…”

“…It was noted that MSTN gene is located between the two significant SNPs at 68490208 -66495180 bp. 11 Sequence variants described on specific locus of MSTN gene seems to be correlated with different morphological types, 43 which may increase the chance for superior performance, especially for sprinter Thoroughbreds, however whether these genomic markers are linked with physiological capabilities such as repeated sprint ability, peak power output and maximal accumulated oxygen deficit (MAOD) remains unknown. In humans an initial effort has been done in order to identify genetic variations of known muscle mass and muscle strength cohorts.…”