
An analysis of the genes of renowned sledge dog Balto, long believed to be a Siberian husky, reveals he was a mixture of different Arctic and Asian breeds.
Balto is perhaps the most famous sledge dog of all time, celebrated for leading his musher and team on a harrowing 85-kilometre journey across the Alaskan interior to deliver diphtheria medication to sick children in the town of Nome in 1925.
To understand how Balto’s genes compared to those of modern dogs and contributed to his success as a sledge dog, at the University of California, Santa Cruz, and her colleagues took skin samples from Balto’s taxidermied remains. They compared Balto’s genome – the complete set of DNA in his cells – to those of nearly 700 different dogs and wolves from 135 different breeds or populations.
Advertisement
As suspected, Balto had Siberian husky heritage, but he also shared a significant portion of his genes with Greenland sledge dogs, Vietnamese village dogs and Tibetan mastiffs. He had an overall greater genetic diversity – a range of inherited traits – than modern sledge dog breeds like Alaskan Malamute and Siberian husky.
“It is super interesting to see that his ancestry derived from all of these different dog groups” instead of from a specific modern sledge dog breed, says Shapiro.
Because Balto was a mixture of breeds, he had a lower risk of developing diseases that can arise in inbred dogs. The team also found he had versions of genes that have been linked to heightened endurance, which may have helped Balto excel as a sledge dog.
The genetic analysis also helped paint a more complete picture of what Balto looked like. Balto had genes matching features in historical photos and his remains: a Siberian husky-sized dog with thick, dark fur fringed in white and tan.
Peeking into Balto’s genes “brings the past back to life”, says at the US National Institutes of Health, who wasn’t involved with the research. “Balto had a job to do, and they didn’t care what he looked like.”
Science