2014 年 3 巻 2 号 p. 229-234
Satellite cells are skeletal muscle tissue stem cells located between the basal lamina and sarcolemma of myofibres and play crucial roles in adult muscle repair and regeneration as well as postnatal muscle growth. More and more findings indicate that satellite cells exist as a genetically and functionally heterogeneous population among muscles, which is not only based on fibre types, but also embryonic origin. Satellite cells are also a heterogeneous population even within a single myofibre. Only a small population of satellite cells possesses “stemness” and exhibits remarkable regeneration with a high self-renewal ability when transplanted into injured muscles. Recent studies have shed light on the cellular and molecular characteristics of satellite cell heterogeneity including Pax7+Myf5- cells, satellite-side population cells, Pax7-nGFPhigh cells, and slow-dividing cells. Here, we review recent progress in our understanding of the heterogeneity and stem cell hierarchies in the satellite cell population.