We also used smFISH to examine the expression of
cdh-4 and
cdh-3. Consistent with transgenic reporter studies (Sundararajan et al., 2014), we observed
cdh-4 mRNA spots in the Q neuroblasts, as well as a wide range of other cells, including the neighboring seam and P cells, ventral nerve cord neurons and cells in the head region. In contrast, we found that during the initial polarization and migration phase,
cdh-3 was specifically expressed in the Q neuroblasts, with additional expression only in a few unidentified cells in the head. Similar to
unc-40, there was no significant difference in expression between QL and QR. Moreover, for both
cdh-3 and
cdh-4, the expression level correlated with migration distance (
cdh-3 QL, Spearman r = 0.5765, p < 0.0001, QR, Spearman r = -0.4838, p < 0.0004;
cdh-4 QL, Spearman r = 0.3176, p < 0.03, QR, Spearman r = -0.5070, p < 0.0004), indicating that expression increases during polarization and migration.