Fig. 6.

N-cadherin and N-CAM are required to maintain otic placode morphology. A. Loss of N-cadherin mimics the absence of Pax2. At the 16–18 somite stage, cells carrying control MOs show elongated shape (top row) and N-cadherin expression apically (magenta); panel on the right shows an overview of the same section with both placodes. In contrast, the placode does not thicken or invaginate in N-cadherin knock downs (bottom row, open arrow heads) and cells remain cuboidal. N-cadherin expression is lost (magenta) in the targeted side, but present on the contralateral side (panel on the right). B. Loss of N-CAM mimics the absence of Pax2. Control electroporated cells (top row) are elongated at the 13–15 somite stage and express N-CAM (red) and Pax2 (blue). In contrast, cells carrying N-CAM MOs (bottom row) are round (open arrow head), have lost N-CAM expression (red), but continue to express Pax2 (blue). Panels on the right show a low magnification to include the contralateral placode for comparison. C. Twenty representative cells from control, N-cadherin and N-CAM MO carrying cells show the difference in cell shape. D. The elongation index of cells expressing N-cadherin or N-CAM MOs is significantly reduced when compared to control electroporated cells (WT 13–16ss). For comparison the EI for placode cells from 6 somite embryos is included. Graph shows mean values ± standard deviation.