Complete horse genome sequence unveiled

Davis, Calif.

-- The complete sequence of the domestic horse has been uncovered by researchers at the University of California-Davis (UC-Davis), the Broad Institute at MIT and Harvard University and were set to be released in the Nov. 6 issue of the journal

Science

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The findings have important implications for equine breeding, a $39 billion industry in the United States, according to UC-Davis officials.

"This very high-quality genome sequence of the horse is important because it gives us access to specific sequence information that we can now apply to identify the genes for specific traits in the horse," says Cecilia Penedo, a UC-Davis Veterinary Genetics Laboratory geneticist and co-author of the study.

As a collaborator on the international study, titled Horse Genome Project, Penedo supplied DNA from Arabian and Quarter horses. The study findings note more than 90 hereditary conditions that affect both humans and horses.

“Because horses share these conditions, which include infertility, inflammatory diseases and muscle disorders, the horse is an important model for improving the understanding of human diseases,” UC-Davis reports. “The sequencing project revealed that the horse genome is somewhat larger than the dog genome and smaller than the human and cow genomes. In comparing the horse and human chromosomes, the researchers discovered that 17 out of 32 horse chromosome pairs -- 53 percent -- are composed of material from a single human chromosome, while only 29 percent of dog chromosomes are composed of material from a single human chromosome. This indicates that fewer chromosome rearrangements separate humans from horses than separate humans from dogs.”

The study also unveiled an “evolutionarily” new centromere, a key structural feature of chromosomes, on horse chromosome 11 that could reveal models to study factors cell activity. The full sequencing will help researchers map various traits of the horse, says Penedo.

The genome project was funded by the National Human Genome Research Institute, the Dorothy Russell Havemeyer Foundation, the Volkswagen Foundation, the Morris Animal Foundation, and Italy's Programmi di Ricerca Scientifica di Rilevante Interesse Nazionale.