Neural crest cell interactions and the creation of the cranial ganglia
Once neural crest cells become migratory, they associate with other cell types, such as placode cells, to form specific derivatives, including the cranial trigeminal ganglia. The proteins responsible for mediating these associations remained elusive until we identified critical players involved in this process. We have now shown that migratory neural crest cells express αN-catenin and Cadherin-7 (Cad7) during their interactions with placode cells, and that αN-catenin levels must be tightly controlled to allow for productive neural crest-placode cell associations. Using innovative tools, such as photo morpholinos and inducible expression constructs, as well as novel biochemical approaches, we aim to identify and characterize the types of cellular junctions that exist between neural crest cells, placode cells, and the extracellular environment in order to properly form the cranial ganglia.
Electroporation of a morpholino (MO, red) to knock-down αN-catenin translation in migratory neural crest cells impacts the later formation of placode cell-derived neurons (labeled with an antibody to Tubb3, green) within the trigeminal ganglion (A, arrows), with no effect on the contralateral control side of the same embryo (B). e, eye; TG, trigeminal ganglion. Scale bar in (A) is 100 µm and applicable to (B). Adapted from Wu et al., 2014.