Fig. 7.

pLLP cell polarity is largely unaffected in mcf2lb mutants. (A-J′) Immunostaining for the tight junction marker ZO-1 in WT and mutant pLLPs at 45 hpf. Panels A-J show the lateral (top-down) view, A′-J′ show an apical-basal view (images were digitally rotated 90° around x-axis; dashed lines in A,B,F,G). All images are z-projections. Dotted lines indicate the pLLP in B and F and NMs in B-E and G-J. Note the ring structure and the apical localization of ZO-1 in the trailing-most rosette and deposited NMs in WT. In contrast, ZO-1 signal is disorganized in mc2lb mutants. (K) Quantification of the percentage of apical- and basal-localized ZO-1 signal in the pLLP in WT (n=8 pLLPs) and mcf2lb mutants (n=13 pLLPs). (L) Quantification of the percentage of apical- and basal-localized ZO-1 signal in NMs in WT (n=15 NMs from four embryos) and mc2lb mutants (n=26 NMs from five embryos). (M-N′) Par-3-tagRFP expression in WT and mcf2lb mutant pLLPs. Panels M and N show the lateral (top-down) view, panels M′ and N′ show an apical-basal view (images were digitally rotated 90° around x-axis; dashed lines M,N). All images are z-projections. Note Par-3 localization to the rosette centers and the midline in WT embryos; in contrast, Par-3 is localized to the midline but not organized into rosette centers in mcf2lb mutants. Par-3 is apically localized in both WT and mcf2lb mutant pLLPs. (O) Quantification of the percentage of apically- and midline-localized Par-3 signal in WT (n=7 pLLPs) and mcf2lb mutants (n=8 pLLPs). ***P<0.001 (unpaired two-tailed t-test). n.s., not significant. Error bars are s.d. Scale bars: 10 μm (A,F,M,N); 5 μm (B-D,G-J).