In a surprising discovery with implications for treating muscular dystrophy, researchers at the University of Utah School of Medicine and other institutions have identified a major source of origin for two groups of adult cells that regulate muscle repair. The researchers found that these muscle repair cells, satellite and side population (SP) cells, arise from somites--transient blocks of tissue in the embryo that give rise to muscle, vertebrae, and the inner layer of skin called the dermis. The origin of satellite and side population (SP) cells has engendered considerable debate. Published in the Jan. 24 issue of the Proceedings of the National Academy of Sciences, the study shows that a significant number of satellite and SP cells arise from somites. The researchers also found that SP cells originating from somites are much better at forming muscle than SP cells not produced by somites.
