BROOKS EQUINE GENETICS
Identification of genetic components of gait-type
Picture by Kiko Catelli
GRILLNER, S. & WALLEN, P. 1985. Central pattern generators for locomotion, with special reference to vertebrates. Annual review of neuroscience, 8, 233-61.
IJSPEERT, A. J. 2008. Central pattern generators for locomotion control in animals and robots: a review. Neural networks : the official journal of the International Neural Network Society, 21, 642-53.
KULLANDER, K., CROLL, S. D., ZIMMER, M., PAN, L., MCCLAIN, J., HUGHES, V., ZABSKI, S., DECHIARA, T. M., KLEIN, R., YANCOPOULOS, G. D. & GALE, N. W. 2001. Ephrin- B3 is the midline barrier that prevents corticospinal tract axons from recrossing, allowing for unilateral motor control. Genes & development, 15, 877-88.
KUO, A. D. 2002. The relative roles of feedforward and feedback in the control of rhythmic movements. Motor control, 6, 129-45.
PATTERSON, L., STAIGER, E. A. and BROOKS, S. A. (2015), DMRT3 is associated with gait type in Mangalarga Marchador horses, but does not control gait ability. Animal Genetics, 46: 213–215. doi: 10.1111/age.12273
STAIGER, E. A. B., BELLONE, R. R.; SUTTER, N. B.; BROOKS, S. A. 2011. Genome-wide association of polymorphic gait in the horse. Journal of Animal Science, 89, 321.
If you own gaited horses, we need you!
Have you ever asked yourself why do some horses gait? Horses are, indeed, the only known species of mammals that has such a wide variation in locomotion patterns. The gait is influenced by several factors: conformation and neurobiology, and to some extent environmental factors - such as human intervention in the form of shoeing and training. Each of the physiological aspects is influenced by other numerous components. The conformation by the bone length and thickness, muscle fiber type and joint angles. Types of nerves, presence and amount of calcium and potassium transmitters and synapse receivers control the neurobiology.
Several genes affect each of these components is therefore unlikely that a single gene is responsible for gaiting, but a combination of specific genes and their alleles. And in order to discover which genes are responsible for gait in horses, we need gaited horses! The goal of this study is to identify which genes predispose horses to gait, when compared to trotting or pacing horses. We need hundreds and hundreds of horses; the more horses that participate, the more successful our study will be.
Previous studies in the Brooks lab revealed within the Tennessee Walking Horse, a North American gaited horse breed, four markers residing adjacent to genes important for neural function and that explains 48% of the variance within this population.
Based on the hypothesis that gait pattern and cadence is a natural and inherent feature of various equine breeds, primarily controlled by the central pattern generators (CPG). Located within the central medulla, the CPG neural network generates programming based on a genetically determined spinal circuit, producing a synapse rhythm unique to each gait type. Gaited breeds, as the Mangalarga Marchador, Paso Fino and Tennessee Walking Horse, are under intense selective pressure for gait and other criteria, and are ideal candidates for the identification of genetic components that control gait-type. Differentiation of their movements by consistent required evaluation of gait in each horse by well-qualified and trained professionals provide outstanding phenotypic measures of gait-type.
Our genetic studies will identify markers for genes associated with the characteristic gaits of horse breeds, creating a genetic diagnostic tool that will an innovative approach to genetic breeding selection, allowing owners to appropriately select and direct their breedings accordingly, making genetic improvement of the breed based on proven data. The identification of candidate genes at these loci will also illuminate neuronal control of a complex behavioral phenotype and may be applicable in future research of these mechanisms.
How can I enroll my horse(s)?
Horses need to be registered within the breeders association.
This requirement is necessary because breed associations have specialized competitions that verify gait quality, so this keeps control of the breed gaitedness.
For the gait study, from each horse we are collecting:
And finally, a consent form from each breeder/owner. You can download the necessary documents on the button below:
Please, mail the paperwork to:
Brooks Equine Genetics Lab
2033 Mowry Road
Gainesville – FL 32610
United States of America
If you still have any questions, please don't hesitate in contacting either our lab (352)273-8080 firstname.lastname@example.org or e-mail Laura Patterson Rosa (email@example.com). You can also e-mail us a link for your horse's video.