Figure 5

Functional analysis of xPAPC during otic development. (A, B) Coinjection of different functional xPAPC domains with xPAPC Mo. (A) Constructs that were coinjected in (B), comprise of six characteristic extracellular cadherin domains (orange), transmembrane domain (blue), gap43 membrane anchor (red) or cytoplasmic part (yellow). All used constructs were tested for successful expression in a radioactive TNT assay. (B) 500 pg RNA were coinjected with xPAPC Mo into one blastomere of 2-cell stage. At stage 26 the embryos were examined via ISH for Tbx2. The data are normalized relating to uninjected wildtype embryos. Only coinjection of FL-PAPC showed reconstitution, C-PAPC and C-PAPCgap partially rescued. (C, D) ISH for PCNS at tailbud stage (stage 28). (D) Enlarged head shows a strong signal in the otic region, as well as in branchial arches. (E) Reconstitution analysis of xPAPC Mo through coinjection of classical cadherins or PCNS. 500 pg of RNA were coinjected with xPAPC Mo into one blastomere of 2-cell stage. At stage 26 the embryos were examined via Tbx2 ISH. The data are normalized relating to uninjected wildtype embryos. xPAPC function in inner ear development could be replaced by the protocadherin PCNS but not by classical cadherins. C, cytoplasmic; FL, full-length; M, membrane; Mo, antisense morpholino; n, number of embryos; SP, signal peptide; TM, transmembrane domain. Scale bar 500 μm. * = p < 0,05; ** = p < 0,01