Fig. 7. Models for the production of the myotome from the dermomyotome. (A-F) Represented above are the two pools of precursors in the dermomyotome (d), in the middle the myotome (m), and below (horizontal thin lines), the clones resulting from labelling of a precursor in the dermomyotome. The clonal boundary in the dermomyotome is represented as a black vertical line. Arrows indicate the genealogical relations between precursors and the myocytes. (A) Non-regionalised model based on extensive cell mixing of the precursors and of the myocytes. (B) Non-regionalised model based on two stem cell systems located in the edges of the dermomyotome. (C) Non-regionalised model based on two stem cell systems located in the central part of the dermomyotome. (D) Regionalised model with a direct relationship between the precursors and the myocytes. (E) Regionalised model with an inverted relationship between the precursors and the myocytes. (F) Regionalised and temporal model based on two stem cell systems with rapid recruitement and loss of new cells. The pool is first composed of black cells that contribute to the myotome (vertical arrows) and self-renew in the dermomyotome (horizontal arrows). These black cells are progressively replaced by the gray cells and then by the white cells.