A gene that helps control muscle development makes all the difference between an elite racing dog and a freak that is put down at birth, scientists reported on Tuesday.

Racing whippets that carried one copy of the mutated gene were among the fastest runners, but those that carried two copies became unattractively bulky and were usually destroyed by breeders, the researchers said.

The next step may be to look for this gene in human athletes to see if it helps explain what makes some competitors excel, said Elaine Ostrander of the National Human Genome Research Institute, who led the study.

The gene controls a muscle protein called myostatin. "Our work is the first to link athletic performance to a mutation in the myostatin gene and could have implications for competitive sports in dogs, horses and possibly even humans," Ostrander said.

Ostrander’s team has been studying dogs to find the genes for various traits and just last month reported that a gene called IGF1 was responsible for making small dogs small. They believe this has implications for differences in human size, as well.

While studying whippets, a small, very thin racing breed, they noticed ones that were big and bulky called "bully" whippets. "They were very, very heavily muscled," Ostrander said. "We were really struck by their remarkable physical appearance."

But breeders do not like them. "The bottom line is, these dogs are not given a chance. When they are born, breeders in this community will describe their appearance as grotesque," she said.

Via the Times of India