Figure 1.

Inhibition of the formation of postsynaptic structures by dsRNA. (A) Schematic representation of the injection of cDNA constructs at nonsynaptic regions of single muscle fibres of rat soleus muscle (left). The injection pipette contains expression plasmids NLS_GFP and neural agrin. dsRNA was added in RNAi experiments. Injected muscle fibres contain GFP-positive myonuclei (green) and aggregates of postsynaptic proteins including AChRs (red). The frame symbolizes the view shown in (B). Postsynaptic structures formed on the surface of the injected and on nearby muscle fibres when no dsRNA (B) or dsRNA_CD4 (C) was included. Injection of dsRNA_MuSK (D) and dsRNA_rapsyn (F) prevents the formation of postsynaptic structures on injected muscle fibres but not on nearby fibres. Postsynaptic structures formed on muscle fibres injected with dsRNA_Sgca (E) and dsRNA_utrophin (G). Scale bars=50 μm.