Horse genome sequence and analysis published in Science

Work provides a critical community resource for horse -- and potentially human -- disease research

An international team of researchers has decoded the genome of the domestic horse Equus caballus, revealing a genome structure with remarkable similarities to humans and more than one million genetic differences across a variety of horse breeds. In addition to shedding light on a key part of the mammalian branch of the evolutionary tree, the work also provides a critical starting point for mapping disease genes in horses.

"Horses and humans suffer from similar illnesses, so identifying the genetic culprits in horses promises to deepen our knowledge of disease in both organisms," said senior author Kerstin Lindblad-Toh, scientific director of vertebrate genome biology at the Broad Institute of MIT and Harvard and a professor of comparative genomics at Uppsala University in Sweden. "The horse genome sequence is a key enabling resource toward this goal."

For centuries, horses have been close human companions. The animals were first domesticated 4,000 to 6,000 years ago and were harnessed primarily for power and transportation. Over time, as machines have become the chief sources of agricultural and industrial muscle, those roles have shifted to mainly sports and recreational activities.

Predating this coexistence, humans and horses share an evolutionary history that has implications for the health of both species. Like other mammals, the two species share much of the same DNA. Moreover, horses suffer from more than 90 hereditary diseases that show similarities to those in humans. Recognizing the need for genomic tools to foster biomedical research on horses as well as humans, a research consortium led by scientists at the Broad Institute of MIT and Harvard launched a project three years ago to decode the horse's genetic blueprint. The effort was based on a ten-year collaboration among an international group of scientists to exploit genomic technologies for the benefit of equine health known as the Horse Genome Project.

"We are especially grateful to our collaborators in the horse genetics community who participated in this project," said Lindblad-Toh. "We really could not have done this work without them."