At the Institute for Equine Genomics at Bingham University researchers worked to better understand the genetics behind breeding success in horses. Gene variants are one component they look at to determine if a horse could be a great racehorse. Seabiscuit is a legendary racehorse that does not fit the typical characteristics of a great thoroughbred. He was small, “lazy”, and completely written off after losing his first 17 races. However, after beating Triple Crown winner War Admiral as an underdog, he was voted 1938 Horse of the Year.
A few years ago, Jacqueline Cooper from the Seabiscuit Heritage Foundation got in touch with the Institute, asking if they could test a fifth-generation of Seabiscuit for breeding purposes as well as learning more about the ancestor’s genetics. Because the relationship was so distant, this wasn’t possible. Instead, they extracted a DNA sample from Seabiscuit’s silvered hooves. Removing and preserving a champion racehorse’s hooves was once customary. The owner kept them as keepsakes and decorative mementos.
Student Kate DeRosa and Andy Merriweather, director of the campus Ancient DNA and Forensic Laboratory, drilled into the coffin bone of the hooves. The coffin bone is the bottommost bone in a horse’s hoof. After extraction they found that the mitochondrial DNA was still intact. This DNA allowed the researchers to verify the maternal lineage and prove that the hooves did, in fact, belong to Seabiscuit. They also found that the nuclear DNA had been degraded due to its age and the chemical treatment it underwent while being silvered. Despite this, Kate was still able to sequence genes associated with optimal racing distance. They found that Seabiscuit had variants that are found in successful distance runners. Most interesting was that his genes also included minor variants found in good sprinting horses. This rare combination explains Seabiscuit’s record. He won races by both very short and extremely long distances.
When looking at successful racehorses today that have a genotype similar to Seabiscuit’s, they tend to be late bloomers when compared to other genotypes. This is much like Seabiscuit’s career; he didn’t begin winning until he was 4. The Institute will continue sequencing Seabiscuit’s genes looking for links to physical attributes as well as temperament traits. They theorize that Seabiscuit could have had behavioral genes that filled him with such a desire to win that it overpowered his less than ideal physical traits. They are interested to see how his DNA differs from modern racehorses knowing how different thoroughbreds looked in the past. The researchers also mention that it is not currently possible to clone Seabiscuit due to the low quality of nuclear DNA.
Tammariello, Steven. “Scientists Extract DNA From Seabiscuit's Hooves To Figure Out How He Was So Fast.” Smithsonian.com, Smithsonian Institution, 29 Oct. 2018, www.smithsonianmag.com/history/scientists-extract-dna-from-seabiscuits-hooves-to-figure-out-how-he-was-so-fast-180970649/.