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Fig. 2. Synapse formation is rescued in Musk mutant mice expressing
MCK-MMT or MCK-Musk. (A) Motor axons terminate at AChR
clusters in muscle from E18.5 Musk mutant embryos carrying
MCK-MMT or MCK-Musk. In E18.5 Musk mutant embryos,
motor axons fail to stop or differentiate, and AChR clusters fail to form. (B)
Synapses are singly innervated in muscle from 3-week-old
Musk-/-; MCK-MMT mice, similar to wild-type and
Musk-/-; MCK-Musk mice. Wholemounts of diaphragm muscles
were stained with antibodies to neurofilament (green) and synaptophysin
(green) to label axons and presynaptic nerve terminals, respectively, and with
Texas-Red
-Bungarotoxin (red) to label AChRs. Scale bar: 15 µm in A;
20 µm in B.