Fast muscles, such as the thigh muscle in a sprinter, deliver energy quickly but fatigue quickly. Slow muscles, such as the soleus muscle in the lower calf, are less forceful but important for posture and endurance. New research points to the discovery on one gene regulator that maintains the fast muscle type and inhibits the development of a slow muscle type.

Researchers from the University of Texas Southwestern Medical Center and Virginia Tech made the discovery.

“Based on previous studies by our group and others, we knew that a gene regulator called Sox6 promotes development of fast muscle in the embryo,” said Olson, professor of molecular biology. “But the function of Sox6 in adult muscle was unknown.”

“Concerted regulation of myofiber-specific gene expression and muscle performance by the transcriptional repressor Sox6,” was published in the Proceedings of the National Academy of Sciences‘ online early edition on June 1.