SHE is the mare that transformed plodders into the kings of the turf.
A quirk of fate and a mutant gene meant that a single mare living in Britain around 300 years ago is responsible for the lightning-quick racehorses seen on the track today.
Scientists at University College Dublin have traced the 'speed gene' to that unnamed mare who was recorded in a 1791 stud book which detailed all the thoroughbred mares and stallions being bred in Britain and Ireland at the time.
Showing the power of breeders to shape the genetic make-up of horses, she is responsible for passing down the C-type speed gene to half of all modern thoroughbred racehorses alive today.
All modern variants of the speed gene have been traced to the legendary Nearctic (1954-1973), which sired Northern Dancer (1961-1990), one of the most influential stallions of modern times.
Dr Emmeline Hill, genomics scientist at UCD, identified the speed gene two years ago and, since then, has been working with researchers at the University of Cambridge in England to find out where it came from.
There are two variants of the gene -- C-type and T-type. Horses with the former are best suited to sprint-like races, while those with the latter have more stamina and perform best over longer distances.
The scientists examined museum bone and tooth specimens from 12 supremely talented thoroughbreds dating from the 18th and 19th centuries -- including Eclipse, the undefeated British thoroughbred foaled in 1764. However, none of the horses had the lightning-quick C-type gene.
Researchers then analysed over 600 DNA samples from horses from around the world, focusing on the populations in Britain and Ireland, as well as the Middle East. It was the importation of stallions from the Middle East, which were then bred with mares from Britain and Ireland, that led to the creation of thoroughbreds.
"The highest level of the speed gene type was found in Shetland horses, so this means the speed gene most likely originated from a local British population," explained Dr Hill. "We looked at the variation around the gene and were able to tell it only entered the population once -- from a mare of British origin."
The mare was one of 40 named in the 1791 stud book.
"The speed gene had an opportunity to proliferate in the population as a result of Northern Dancer and also by the big change in racing which moved from four miles to sprint- type races. So over time . . . the speed gene increased in frequency," explained Dr Hill.
Dr Hill, whose grandmother Charmian owned Dawn Run, the only horse to win the Champion Hurdle and the Gold Cup double at Cheltenham, stressed there was no guarantee two sons or daughters would carry the same genetic make-up.
Dr Hill and renowned trainer and breeder Jim Bolger are founders of Equinome, a UCD company which has developed a test for the horsebreeding industry which pinpoints if a particular horse is best suited to short, medium or longer distance racing, while breeders use it to make more precise selection and breeding decisions.