Extended Data Fig. 1: Characterization of neuromuscular synapses in Dok7 mutant mice.
From: Mechanism of disease and therapeutic rescue of Dok7 congenital myasthenia
a, b, Left, diaphragm muscles from E18.5 (a) and P135 (b) wild-type and Dok7 mutant mice were stained with Alexa 488–anti-BGT to label AChRs (red) and antibodies against neurofilament and synapsin to label motor axons and nerve terminals (green). Scale bars, 50 μm (a), 10 μm (b). a, Right, endplate width, denervation and co-localization of synapses in wild-type, Dok7CM/CM and Dok72YF/2YF mice. The width of the endplate band (dashed lines) was increased by 45% in Dok7CM/CM mice but was normal in Dok72YF/2YF mice. In Dok7CM/CM mice, 17% of AChR clusters were completely unopposed by nerve terminals, indicating denervated myofibres. Many synapses in Dok7CM/CM mice were partially innervated, as nearly half of the AChR-rich area at synapses was not juxtaposed by nerve terminals. b, Right, in Dok72YF/2YF mice, synapses mature from a plaque-like to a complex, pretzel-like shape, characteristic of mature mouse neuromuscular synapses. Synapses in Dok72YF/2YF mice, however, often appeared elongated. The number of synapses and the density of synaptic AChRs were similar in wild-type and Dok72YF/2YF mice. Synaptic size was increased by 20% in Dok72YF/2YF mice when compared with wild-type mice. Data shown as mean ± s.e.m. from 3 mice (>50 synapses per mouse). n.s., not significant; *P < 0.05, ****P < 0.00005; two-sided Student’s t-test.
