Pedigree Query

Posted: **Fri Jan 23, 2015 10:29 am**

Just found a study that found her variant of the MSTN gene only in the TB and QH.
http://www.ncbi.nlm.nih.gov/pubmed/25273961
This study suggests that it's the SINE insertion (tested in the first study) that has the speed effect.

Haplotype diversity in the equine myostatin gene with focus on variants associated with race distance propensity and muscle fiber type proportions.
Petersen JL1, Valberg SJ, Mickelson JR, McCue ME.
Author information
Abstract

Two variants in the equine myostatin gene (MSTN), including a T/C SNP in the first intron and a 227-bp SINE insertion in the promoter, are associated with muscle fiber type proportions in the Quarter Horse (QH) and with the prediction of race distance propensity in the Thoroughbred (TB). Genotypes from these loci, along with 18 additional variants surrounding MSTN, were examined in 301 horses of 14 breeds to evaluate haplotype relationships and diversity. The C allele of intron 1 was found in 12 of 14 breeds at a frequency of 0.27; the SINE was observed in five breeds, but common in only the TB and QH (0.73 and 0.48 respectively). Haplotype data suggest the SINE insertion is contemporary to and arose upon a haplotype containing the intron 1 C allele. Gluteal muscle biopsies of TBs showed a significant association of the intron 1 C allele and SINE with a higher proportion of Type 2B and lower proportion of Type 1 fibers. However, in the Belgian horse, in which the SINE is not present, the intron 1 SNP was not associated with fiber type proportions, and evaluation of fiber type proportions across the Belgian, TB and QH breeds shows the significant effect of breed on fiber type proportions is negated when evaluating horses without the SINE variant. These data suggest the SINE, rather than the intron 1 SNP, is driving the observed muscle fiber type characteristics and is the variant targeted by selection for short-distance racing.

And a new database on Single Nucleotide Polymorphism and Expression in the Thoroughbred horse:http://snugenome2.snu.ac.kr/HSDB
http://www.ncbi.nlm.nih.gov/pubmed/25178365

Posted: **Sun Jan 25, 2015 9:41 am**

vineyridge wrote:Just found a study that found her variant of the MSTN gene only in the TB and QH.
http://www.ncbi.nlm.nih.gov/pubmed/25273961
This study suggests that it's the SINE insertion (tested in the first study) that has the speed effect.
Haplotype diversity in the equine myostatin gene with focus on variants associated with race distance propensity and muscle fiber type proportions.
Petersen JL1, Valberg SJ, Mickelson JR, McCue ME.
Author information
Abstract

.......The C allele of intron 1 was found in 12 of 14 breeds at a frequency of 0.27; the SINE was observed in five breeds, but common in only the TB and QH (0.73 and 0.48 respectively).....

The advertised emphasis of Equinome, the company Hill co-owns, is on the Intron 1 variant. It's also been the primary focus of most of the published reports associated with that source although iirc they've mentioned the SINE insertion in the promoter region in passing as a possible functional MSTN variant.

Neither the Intron 1 derived 'C' (speed) variant nor the SINE insertion is exclusive to the TB & QH, just found at greater frequency there, most likely as a result of positive selection pressure. As reported in the abstract, Petersen et al. found the Intron 1 'C' variant in 12 of 14 breeds sampled. It's been reported elsewhere in a few additional breeds/types and apparently occurs in an array of breeds/types that are pretty diverse by geography & conformation.

Not so much the SINE insertion. Petersen et al. found it in 3 breeds additional to TB & QH, the Florida Cracker, Mangalarga Paulista & Missouri Fox Trotter. Elsewhere, as far as I know the only other breed in which it's been documented is the Uruguayan Creole.

Posted: **Mon Jan 26, 2015 8:44 am**

I made a mistake. The Italian study was on the SINE insertion, not the MSTN gene itself.

Posted: **Fri Sep 25, 2015 6:05 am**

Something to consider in relation to the speed gene

http://www.bloodhorse.com/horse-racing/articles/94650/guest-analysis-going-the-distance

Posted: **Fri Oct 16, 2015 4:55 pm**

interesting research Byron. Now if you guys can find the 'class' gene we would really be in business. Well, I wouldn't, but the guys with $$$ would be... I would love to see some true Classic horses (genetically) begin to dominate the gene pool and rebalance things.

jm

Posted: **Sat Oct 31, 2015 6:27 am**

New paper....

Genome-wide evolutionary and functional analysis of the Equine Repetitive Element 1:an insertion in the myostatin promoter
affects gene expression - http://www.biomedcentral.com/content/pdf/s12863-015-0281-1.pdf

Interesting take away in regards to the C:T polymorphism of Equinome and the SINE/ERE1 insertion...

Although the g.66493737C > T SNP showed an association with racing performance [29], this sequence variation does not provide an immediate functional explanation of this trait. On the contrary, our experimental data strongly suggest a direct influence of the ERE1 insertion on myostatin expression. Since the g.66493737C > T SNP is located only 1605 bp away from the ERE1 insertion site in the promoter, the ERE1 insertion, rather than the g.66493737C > T SNP (located in the first intron), may functionally influence racing performance, the two polymorphisms being in linkage disequilibrium (r2= 0.73) as previously observed [29, 46]. In other words, the results presented here on myostatin expression provide a physiological interpretation of the correlation between ERE1 insertion and racing performance; moreover, the previously described correlation among the g.66493737C > T SNP, muscle mass [43] andmuscle fiber composition [46] can also be reinterpreted on the basis of the linkage disequilibrium between the two polymorphic loci.

Pedigree Query

E Hill's speed gene

E Hill's speed gene

Re: E Hill's speed gene

Re: E Hill's speed gene

Re: E Hill's speed gene

Re: E Hill's speed gene

Re: E Hill's speed gene