Dr. Brooks poses with Twilight, the genome horse at the McConville Farm, Cornell University. Twilight is the first horse to have her genome sequenced.
I currently have a USDA grant to research the use of gene expression to monitor mast cell activity in the progression of equine laminitis. Equine laminitis is one of the most significant diseases affecting horses by any measure. The cause of the disease appears to be heterogeneous, occurring as a result of injury, infection, toxins or metabolic disorder. Veterinary scientists are investigating several mechanisms to understand the cause and treat the disease. Two major objectives are development of 1) a prognostic test to identify horses at risk, and 2) a therapeutic treatment to prevent or ameliorate the disease.
Multiple theories exist for the initiating biological pathways of laminitis, all of which can be tied biologically to the action of mast cells (MCs) and MC mediators. We have preliminary data suggesting that investigation of MC related genes KIT (mast cell growth factor receptor) and MTC-1 (mast cell tryptase) may be effective to assay MCs in connection with laminitis. We propose to investigate this hypothesis: Increased numbers of circulating mast cell precursors, and therefore connective tissue mast cells, increases the risk of developing mast cell-mediated inflammation and laminitis. Our specific aims include 1) establishing levels of KIT and MCT-1 in normal horse populations, 2) comparing gene expression levels among healthy horses to those affected by laminitis and 3) investigating the occurrence of these gene transcripts and MCs in healthy and affected hooves. The results will help determine the prognostic value of assaying MCs in connection with laminitis and, more importantly, identify an effective method for assaying the use of pharmacological agents to treat laminitis in horses.
Previous work endeavors in coat color have included the discovery of a polymorphic chromosome inversion that causes the Tobiano spotting pattern in horses. I also studied a polymorphic splice variant responsible for Sabino spotting. As a result, there are now commercial tests available for both these patterns, enabling breeders to make informed decisions about their breeding stock and increase production of desirable traits.
Photo Caption: Dr. Brooks poses with Twilight, the genome horse at the McConville Farm, Cornell University. Twilight is the first horse to have her genome sequenced.
Brooks, S., and Bailey, E. (2005). Exon skipping in the KIT gene causes a Sabino spotting pattern in horses. Mammalian Genome 16:893-902.
Brooks, S., Lear, T.L., Adelson, D., and Bailey, E. (2007). A Chromosome Inversion near the KIT gene and the Tobiano Spotting Pattern in Horses. Cytogenics and Genome Research, 119:3.
Bellone, R., Brooks, S., Murphy, B., Sandmeyer, L., Grahn, B., Forsythe, G., Archer, S., and Bailey, E. Differential gene expression of TRPM1: the likely cause for both coat spotting pattern (LP) and congenital stationary night blindness in the Appaloosa Horse. Genetics.