Each limb muscle is unique with a specific shape, size and insertions to bone via connective tissues,  so the developmental programs of muscle and associated connective tissues have to be tightly regulated to achieve the final muscle pattern. Although each limb muscle is unique, every muscle displays the same organization, they are all attached to tendons at both extremities and innervated at the center of muscle, defining the muscle domains. We found that muscle fusion is not homogenous within muscle but organized according to these domains. We also identified an unexpected recruitment of fibroblast nuclei in muscle fibers, recruitment localized at muscle tips, close to tendon. The spatial regulation of myogenesis is important to shape limb muscles during development.

Delphine Duprez is invited by Pascal Maire.