Fig. 3. Vari is an SJ component. (A-D') Vari localizes to epithelial SJs in the hindgut (A,C) and trachea (A',C') of wild-type animals where it co-localizes with the canonical SJ marker Cor (A,A',B,B'). (D) Schematic diagrams showing the organization of membrane domains and cell-cell junctions in the hindgut (D) and trachea (D'). (E-K) Vari is required for stable formation of SJs, as in vari^F033 null mutants the SJ components Nrx, Sinu and Dlg do not accumulate in a specific region, but instead are mislocalized along the basolateral membrane (F,F',I,I',K,K'). In vari^3953b partial loss-of-function mutants, some SJ components such as Cor (G,G') are almost entirely mislocalized, whereas others such as Dlg only show reduced localization (L,L'). (M-N') Localization of Vari to the SJ depends on other SJ components, as Vari does not specifically localize to the SJ region in nrx (M,M') or nrv2 (N,N') mutants. (O-R) Vari is not required for apical-basal polarity, as localization of the adherens junction and apical markers Arm and Veli is not disrupted in vari^F033 null mutants. (S) Vari protein does not accumulate at SJ regions in animals homozygous for vari alleles that affect the HOOK domain (Table 1). All animals stage 16. Scale bar: in S, 5 µm for all images. WT, wild type.