Figure 4.

Whole mounts of NMJs, 6 weeks after in vivo electroporation of mouse soleus muscle with siRNA plasmids. Electroporated muscle fibres are marked by NLS_GFP (GFP). AChRs were stained to visualize postsynapses, and a mixture of antibodies to neurofilament (Nf) and synaptophysin (Syn) was used to label the presynaptic motor neurons. (A) NMJs are not altered by an siRNA plasmid to CD4. (B–D) Disassembly of NMJs by siRNA plasmids to MuSK. See text for details. Scale bars=15 μm. (E) Quantification of the effect of plasmid-mediated siRNA (see supplementary information online). CD4, siRNA plasmid targeting CD4; M1, M2 and M3, three different siRNA plasmids targeting MuSK. Note that M1 does not show any effect, which is consistent with observations by others that most but not all siRNA constructs are functional (McManus & Sharp, 2002).