Fig. 3

: Distinct cellular and polarity differences between midzone and body of Meckel's cartilage in wls, wnt9a, wnt5b and gpc4 mutants. (A-E) Wnt gene were crossed to Tg(sox10:GFP) transgenic line and homozygote embryos were imaged at difference time points starting at 55 hpf when convergence of the Meckel's cartilage occurs until 96 hpf when the arch is complete. Defects evident from 60 hpf especially in gpc4 -/- and by 72 hpf, obvious midline defect was seen in wls, wnt9a and gpc4 and body defects apparent in gpc4. wnt5b exhibited a smaller cartilage size throughout morphogenesis. (A; 96 hpf) Graphical representation of the L/W measurements from Meckel's cartilage. (A’) 20X image of Meckel's cartilage in the midline and (A′’) 20X image of the body of Meckel's. (F-H) Individual cell length/width ratio were measured and plotted over time from 2 distinct parts of the Meckel's; midzone and body as marked in the illustration. (I-M) 72 hpf WT and homozygote embryos were stained for actin with phalloidin (green) to delineate cell membranes and acetylated-tubulin (red) to reveal microtubule organizing center (MTOC). (N) Polarity pattern for Meckel's cartilage at 72 hpf showing 2 inflection points; point A where the hemi-Meckel's cartilage meet in the midline and point B within the body of each hemi-Meckel's cartilage. (O-S) Rose plots of cell polarity as indicated by MTOC measured from cells within the midzone portion of Meckel's cartilage. (T; black dotted box). Scale=50 µm.