L-AChRs are properly expressed but not detected at the NMJs of oig-4 mutants. (A) The UNC-38 L-AChR subunit cannot be detected by immunostaining at the dorsal cord of oig-4 mutants (ii) when compared with wild-type (WT) animals (i). The pre-synaptic varicosities in oig-4 mutants (iv) form properly as in wild type (iii). ACR-16 N-AChR and UNC-49 GABA receptor distribution in oig-4 mutants (vi, viii) is not affected compared with wild type (v, vii). Scale bar=10 μm. (B) Distribution of the knocked-in UNC-63-YFP L-AChR subunit scored in vivo in oig-4 mutant populations. In the reference knock-in strain (i) UNC-63-YFP is detected in ventral (VC) nerve cord and dorsal nerve cord (not shown). In the oig-4 mutant background UNC-63-YFP is either still detected as weak clusters (ii, group a) or not clustered in the cords (iii, group b) (AF: autofluorescence from intestine). Scale bar=10 μm. (C) Quantification of groups a and b (see B) in WT and oig-4 mutant background. The graph represents results of two independent experiments after blind scoring of 100 animals per experiment for each genotype. (D) Western blot analysis of UNC-29 L-AChR subunit expression. UNC-29 levels were normalized to tubulin A. (Percentage of wild-type levels in the oig-4(kr39) and oig-4(kr193) was 104±6% (n=4) and 134±40% (n=4), respectively, mean±s.d.) Bar indicates the 50 kDa marker.