In mature myofibers, nuclei are positioned at the periphery of the cell with some nuclei clustered at the neuromuscular synapse. However, in immature myofibers, the nuclei accumulate at the cell center. Based on these observations, at least three nuclear movements or positioning events are predicted to occur during muscle fiber formation :
- During syncytial myotube formation, the nuclei of mononucleated myoblasts move from the site of fusion to the center of the myotube;
- During myofiber formation, the nuclei move from the center of the myotube to the cell periphery, and
- During neuromuscular synapse formation, some nuclei become anchored close to the clusters of acetylcholine receptor (AchR), precursors of neuromuscular synapses.
We want to identify the mechanisms and the molecular pathways that regulate these different nuclear movement and position events. We will then be able to study the role of nuclear positioning during myofiber formation and function.
We are also interested in understanding how mutations in different proteins that are associated with muscular dystrophies are involved in nuclear position.
