The distribution of AChR was observed in AChRδ-YFP (+) larva with YFP (A, C and E, G) and in native larvae stained with α-Btx (B, D and F, H) in the wild type (A–D) or the twitch once background (E–H). While the YFP molecule filling the cytoplasm obscures the AChRδ-YFP distribution in twitch once (E, G), the membranous distribution of AChRs is obvious with α-Btx (F, H), which stains only assembled pentamers. Scale: 50μm.