Fig. 3. Septate junction components are mislocalized or dramatically reduced in Na⁺/K⁺ ATPase mutants. In nrv2 mutants (B,D,F,H), Coracle (red, B,H), Discs Large (green, D) and FasIII (red, F) appear to be reduced and/or no longer have the septate junction localization seen in wild-type animals (A,C,E,G). Neurexin staining closely resembled Coracle staining and was mislocalized in nrv2 mutants (data not shown). Localization of Discs Lost (green, E,F), E-cadherin (green, G,H) and Armadillo (data not shown) was unaffected by nrv2 mutations (F,H). ATP null mutations caused the same mislocalization and defects in protein levels as do nrv2 mutations (data not shown). Basal surfaces are outlined in white, apical/lumenal surfaces in blue. For each marker examined, the wild-type and mutant images are matched pairs (e.g. A and B, and C and D), where the wild type is a heterozygous embryo imaged with the same settings, on the same slide, and in the same session as the mutant embryo to provide an internal reference for protein levels. Scale bar: in H'', 5 µm for A-D,A''-D'',E-H''; in D', 5 µm for A'-D'.