Genetics & Genomics
Health and welfare of horses begins with a robust genetic constitution and finishes with effective management. Scientists in this group characterize genetic differences among horses, differences in gene expression between tissues, and changes in gene expression that occur during disease processes and therapeutic interventions. As a result of the Human Genome Project and related research programs, technologies are being developed that enable global investigations of the genome (DNA sequences and gene maps), transcriptome (RNA products of genes and templates for proteins) and proteome (protein products of genes). These new technologies are facilitating efforts by scientists to better understand disease problems, develop improved diagnostic tests, enhance therapeutic approaches, and optimize management practices for the benefit horses and horse owners. Research topics within the Genetics and Genomics group span hereditary diseases, developmental defects of the musculoskeletal system, infectious diseases, reproductive dysfunction and even coat color patterns.
Research Areas
Genomic and transcriptomic sequencing data are being used to address two primary objectives: (1) improve the annotation of equine protein-coding genes, (2) improve the equine reference genome. These efforts resulted in an update of NCBI’s equine gene structure annotation in November 2015. In collaboration with Dr. Ted Kalbfleisch, an improved version of the equine reference genome to be designated EquCab3 is nearing completion.
Genetic factors can determine the outcome of infectious diseases. Horses are not equally susceptible to infectious disease caused by different viruses, bacteria and parasites. Identifying and understanding these differences can lead to development of better vaccines and therapeutic treatments. Ongoing work includes studies of horse responses to equine arteritis virus, equine herpes viruses and influenza viruses.
Mutations in genes can have profound effects on the appearance and health of horses. When a trait is determined by the DNA sequence of a single gene, this is referred to as a Mendelian trait. The availability of genomic tools made it possible to identify the genes and precise variants responsible for a variety of traits including several coat color genes (Tobiano, Sabino, Dominant White, Appaloosa) and several congenital disease genes (Junctional Epidermolysis Bullosa, Dwarfism) and map the location of others (severe combined immunodeficiency disease, extreme lordosis). Ongoing work involves investigations of parrot mouth and contracted tendons of foals.
Performance and some diseases of horses involve the interaction of multiple genes as well as management and environmental factors. Understanding the strength of the genetic contribution to these traits requires studies using a combination of molecular genetics, quantitative genetics and bioinformatics.
