Sunday, January 26, 2014
A single gene controls movement in vertebrates
Traits such as height are determined using as many as 700 genes. So, it comes as a surprise there is only one controlling movement in horses as well as mice. Research has discovered that the gene DMRT3 has been found in an unknown set of neurons in the spinal cord of vertebrates.
Several researchers from Uppsala University have found one very strong signal on one chromosome that has led to the identification of the DMRT3 gene.
Horses were the perfect choice for testing as there are many different variations in locomotion. They have numerous forms of gait, including walc, trot, canter and gallop. Factor in gaited horses with each breed's own form of naturally occurring gait such as the tolt of the Icelandic, the running walk of the Tennessee Walking horse, and the pace found in the American Saddlebred. Scientists wanted to understand why some horses have more variability in their gait than others and began research on how this could be explained.
A single base change in the gene DMRT3 was the result in the shortening of the gene itself. This mutation was associated with pacing in horses. The mutation inhibits the transition from trot to gallop and allows the horse to trot at a very high speed. This is most common in the Tennessee Walking Horse and the Paso Fino breeds.
These Swedish scientists performed further research on the DMRT3 gene in mice and how it affects locomotion. Mice lacking the gene did not develop properly and thus had an altered means of locomotion. These mice could eventually move somewhat normally, which suggests other neurological circuits compensate for the loss of DMRT3. This shows how the neurological system is able to adapt to the absence of key genes.
There are plans to continue further research in experimenting with horses and the DMRT3 gene. The first will have a look at the evolutionary aspect of the origin of the gene and its distribution worldwide. This research is not only valuable in the breeding of horses and other domestic animals, but it will also affect human research as well, in hopes to help those with spinal cord injuries regain the ability to walk.
Brooks Gaited Horse Training