| 18198 | Q61006 | MUSK_MOUSE | Muscle, skeletal receptor tyrosine-protein kinase (EC 2.7.10.1) (Muscle-specific tyrosine-protein kinase receptor) (MuSK) (Muscle-specific kinase receptor) | DISRUPTION PHENOTYPE | Mice die perinatally being unable to take a breath and to respond to tail or leg pinch. Despite the presence of apparently normal skeletal muscle, the absence of differentiated nerve terminals is sufficient to account for this phenotype. Every aspect of NMJ formation examined is absent in these mice. Branches of the main intramuscular nerve do not establish normal contacts with the muscle, do not form correctly positioned or specialized nerve terminals, and are apparently not given appropriate signals to stop their wandering aimlessly across the muscle. Furthermore, postsynaptic differentiation is absent, muscle-derived proteins normally localized to the synaptic basal lamina or the postsynaptic membrane being uniformly distributed in myofibers. {ECO:0000269|PubMed:8653786}. |